diff --git a/src/CallHandler.js b/src/CallHandler.js
index 7403483e36..abbd407e7f 100644
--- a/src/CallHandler.js
+++ b/src/CallHandler.js
@@ -62,6 +62,7 @@ import dis from './dispatcher';
 import { showUnknownDeviceDialogForCalls } from './cryptodevices';
 import SettingsStore from "./settings/SettingsStore";
 import WidgetUtils from './utils/WidgetUtils';
+import WidgetEchoStore from './stores/WidgetEchoStore';
 
 global.mxCalls = {
     //room_id: MatrixCall
@@ -402,18 +403,30 @@ function _onAction(payload) {
 }
 
 function _startCallApp(roomId, type) {
-    dis.dispatch({
-        action: 'appsDrawer',
-        show: true,
-    });
-
     const room = MatrixClientPeg.get().getRoom(roomId);
     if (!room) {
         console.error("Attempted to start conference call widget in unknown room: " + roomId);
         return;
     }
 
-    const currentJitsiWidgets = WidgetUtils.getRoomWidgets(room).filter((ev) => {
+    dis.dispatch({
+        action: 'appsDrawer',
+        show: true,
+    });
+
+    const currentRoomWidgets = WidgetUtils.getRoomWidgets(room);
+
+    if (WidgetEchoStore.roomHasPendingWidgetsOfType(room, currentRoomWidgets, 'jitsi')) {
+        const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
+
+        Modal.createTrackedDialog('Already have pending Jitsi Widget', '', ErrorDialog, {
+            title: _t('Call in Progress'),
+            description: _t('A call is currently being placed!'),
+        });
+        return;
+    }
+
+    const currentJitsiWidgets = currentRoomWidgets.filter((ev) => {
         return ev.getContent().type === 'jitsi';
     });
     if (currentJitsiWidgets.length > 0) {
diff --git a/src/actions/MatrixActionCreators.js b/src/actions/MatrixActionCreators.js
index 6e1d52a88f..d8c315f505 100644
--- a/src/actions/MatrixActionCreators.js
+++ b/src/actions/MatrixActionCreators.js
@@ -183,6 +183,20 @@ function createEventDecryptedAction(matrixClient, event) {
     return { action: 'MatrixActions.Event.decrypted', event };
 }
 
+/**
+ * Create a MatrixActions.RoomState.vents action that represents
+ * a MatrixClient `RoomState.events` matrix event, emitted when the
+ * state events in a room change.
+ *
+ * @param {MatrixClient} matrixClient the matrix client.
+ * @param {MatrixEvent} event matrix event which caused this event to fire.
+ * @param {RoomState} state room state whose RoomState.events dictionary was updated.
+ * @returns {EventDecryptedAction} an action of type `MatrixActions.Event.decrypted`.
+ */
+function createRoomStateEventsAction(matrixClient, event, state) {
+    return { action: 'MatrixActions.RoomState.events', event, state };
+}
+
 /**
  * This object is responsible for dispatching actions when certain events are emitted by
  * the given MatrixClient.
@@ -204,6 +218,7 @@ export default {
         this._addMatrixClientListener(matrixClient, 'Room.timeline', createRoomTimelineAction);
         this._addMatrixClientListener(matrixClient, 'RoomMember.membership', createRoomMembershipAction);
         this._addMatrixClientListener(matrixClient, 'Event.decrypted', createEventDecryptedAction);
+        this._addMatrixClientListener(matrixClient, 'RoomState.events', createRoomStateEventsAction);
     },
 
     /**
diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index 98d700e0a0..5c97b5c29a 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -45,6 +45,7 @@ import { KeyCode, isOnlyCtrlOrCmdKeyEvent } from '../../Keyboard';
 
 import RoomViewStore from '../../stores/RoomViewStore';
 import RoomScrollStateStore from '../../stores/RoomScrollStateStore';
+import WidgetEchoStore from '../../stores/WidgetEchoStore';
 import SettingsStore, {SettingLevel} from "../../settings/SettingsStore";
 import WidgetUtils from '../../utils/WidgetUtils';
 
@@ -153,6 +154,8 @@ module.exports = React.createClass({
         // Start listening for RoomViewStore updates
         this._roomStoreToken = RoomViewStore.addListener(this._onRoomViewStoreUpdate);
         this._onRoomViewStoreUpdate(true);
+
+        WidgetEchoStore.on('updateRoomWidgetEcho', this._onWidgetEchoStoreUpdate);
     },
 
     _onRoomViewStoreUpdate: function(initial) {
@@ -243,6 +246,12 @@ module.exports = React.createClass({
         }
     },
 
+    _onWidgetEchoStoreUpdate: function() {
+        this.setState({
+            showApps: this._shouldShowApps(this.state.room),
+        });
+    },
+
     _setupRoom: function(room, roomId, joining, shouldPeek) {
         // if this is an unknown room then we're in one of three states:
         // - This is a room we can peek into (search engine) (we can /peek)
@@ -319,7 +328,9 @@ module.exports = React.createClass({
             return false;
         }
 
-        return WidgetUtils.getRoomWidgets(room).length > 0;
+        const widgets = WidgetEchoStore.getEchoedRoomWidgets(room, WidgetUtils.getRoomWidgets(room));
+
+        return widgets.length > 0 || WidgetEchoStore.roomHasPendingWidgets(room, WidgetUtils.getRoomWidgets(room));
     },
 
     componentDidMount: function() {
@@ -414,6 +425,8 @@ module.exports = React.createClass({
             this._roomStoreToken.remove();
         }
 
+        WidgetEchoStore.removeListener('updateRoomWidgetEcho', this._onWidgetEchoStoreUpdate);
+
         // cancel any pending calls to the rate_limited_funcs
         this._updateRoomMembers.cancelPendingCall();
 
diff --git a/src/components/views/rooms/AppsDrawer.js b/src/components/views/rooms/AppsDrawer.js
index 04e47f0f9f..64aa8fadc8 100644
--- a/src/components/views/rooms/AppsDrawer.js
+++ b/src/components/views/rooms/AppsDrawer.js
@@ -29,6 +29,7 @@ import ScalarMessaging from '../../../ScalarMessaging';
 import { _t } from '../../../languageHandler';
 import WidgetUtils from '../../../utils/WidgetUtils';
 import SettingsStore from "../../../settings/SettingsStore";
+import WidgetEchoStore from "../../../stores/WidgetEchoStore";
 
 // The maximum number of widgets that can be added in a room
 const MAX_WIDGETS = 2;
@@ -57,6 +58,7 @@ module.exports = React.createClass({
     componentWillMount: function() {
         ScalarMessaging.startListening();
         MatrixClientPeg.get().on('RoomState.events', this.onRoomStateEvents);
+        WidgetEchoStore.on('updateRoomWidgetEcho', this._updateApps);
     },
 
     componentDidMount: function() {
@@ -82,6 +84,7 @@ module.exports = React.createClass({
         if (MatrixClientPeg.get()) {
             MatrixClientPeg.get().removeListener('RoomState.events', this.onRoomStateEvents);
         }
+        WidgetEchoStore.removeListener('updateRoomWidgetEcho', this._updateApps);
         dis.unregister(this.dispatcherRef);
     },
 
@@ -163,7 +166,10 @@ module.exports = React.createClass({
     },
 
     _getApps: function() {
-        return WidgetUtils.getRoomWidgets(this.props.room).map((ev) => {
+        const widgets = WidgetEchoStore.getEchoedRoomWidgets(
+            this.props.room, WidgetUtils.getRoomWidgets(this.props.room),
+        );
+        return widgets.map((ev) => {
             return this._initAppConfig(ev.getStateKey(), ev.getContent(), ev.sender);
         });
     },
@@ -231,7 +237,8 @@ module.exports = React.createClass({
                     waitForIframeLoad={app.waitForIframeLoad}
                     whitelistCapabilities={enableScreenshots ? ["m.capability.screenshot"] : []}
                 />);
-            });
+            },
+        );
 
         let addWidget;
         if (this.props.showApps &&
@@ -250,10 +257,22 @@ module.exports = React.createClass({
             </div>;
         }
 
+        let spinner;
+        if (
+            apps.length === 0 && WidgetEchoStore.roomHasPendingWidgets(
+                this.props.room,
+                WidgetUtils.getRoomWidgets(this.props.room),
+            )
+        ) {
+            const Loader = sdk.getComponent("elements.Spinner");
+            spinner = <Loader />;
+        }
+
         return (
             <div className={'mx_AppsDrawer' + (this.props.hide ? ' mx_AppsDrawer_hidden' : '')}>
                 <div id='apps' className='mx_AppsContainer'>
                     { apps }
+                    { spinner }
                 </div>
                 { this._canUserModify() && addWidget }
             </div>
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index d02ab8ff29..ae4ca74085 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -40,14 +40,11 @@
     "Failed to set up conference call": "Failed to set up conference call",
     "Conference call failed.": "Conference call failed.",
     "Call in Progress": "Call in Progress",
+    "A call is currently being placed!": "A call is currently being placed!",
     "A call is already in progress!": "A call is already in progress!",
     "The file '%(fileName)s' failed to upload": "The file '%(fileName)s' failed to upload",
     "The file '%(fileName)s' exceeds this home server's size limit for uploads": "The file '%(fileName)s' exceeds this home server's size limit for uploads",
     "Upload Failed": "Upload Failed",
-    "Failure to create room": "Failure to create room",
-    "Server may be unavailable, overloaded, or you hit a bug.": "Server may be unavailable, overloaded, or you hit a bug.",
-    "Send anyway": "Send anyway",
-    "Send": "Send",
     "Sun": "Sun",
     "Mon": "Mon",
     "Tue": "Tue",
@@ -87,7 +84,6 @@
     "Failed to invite users to community": "Failed to invite users to community",
     "Failed to invite users to %(groupId)s": "Failed to invite users to %(groupId)s",
     "Failed to add the following rooms to %(groupId)s:": "Failed to add the following rooms to %(groupId)s:",
-    "Unnamed Room": "Unnamed Room",
     "Riot does not have permission to send you notifications - please check your browser settings": "Riot does not have permission to send you notifications - please check your browser settings",
     "Riot was not given permission to send notifications - please try again": "Riot was not given permission to send notifications - please try again",
     "Unable to enable Notifications": "Unable to enable Notifications",
@@ -153,18 +149,59 @@
     "Displays action": "Displays action",
     "Unrecognised command:": "Unrecognised command:",
     "Reason": "Reason",
+    "<target> accepted the invitation for %(displayName)s.": "<target> accepted the invitation for %(displayName)s.",
+    "<target> accepted an invitation.": "<target> accepted an invitation.",
+    "<sender> requested a VoIP conference.": "<sender> requested a VoIP conference.",
+    "<sender> invited <target>.": "<sender> invited <target>.",
+    "<sender> banned <target>.": "<sender> banned <target>.",
+    "<oldDisplayName> changed their display name to <displayName>.": "<oldDisplayName> changed their display name to <displayName>.",
+    "<sender> set their display name to <displayName>.": "<sender> set their display name to <displayName>.",
+    "<sender> removed their display name (<oldDisplayName>).": "<sender> removed their display name (<oldDisplayName>).",
+    "<sender> removed their profile picture.": "<sender> removed their profile picture.",
+    "<sender> changed their profile picture.": "<sender> changed their profile picture.",
+    "<sender> set a profile picture.": "<sender> set a profile picture.",
     "VoIP conference started.": "VoIP conference started.",
+    "<target> joined the room.": "<target> joined the room.",
     "VoIP conference finished.": "VoIP conference finished.",
-    "%(senderDisplayName)s sent an image.": "%(senderDisplayName)s sent an image.",
+    "<target> rejected the invitation.": "<target> rejected the invitation.",
+    "<target> left the room.": "<target> left the room.",
+    "<sender> unbanned <target>.": "<sender> unbanned <target>.",
+    "<sender> kicked <target>.": "<sender> kicked <target>.",
+    "<sender> withdrew <target>'s invitation.": "<sender> withdrew <target>'s invitation.",
+    "<sender> changed the topic to \"%(topic)s\".": "<sender> changed the topic to \"%(topic)s\".",
+    "<sender> removed the room name.": "<sender> removed the room name.",
+    "<sender> changed the room name to %(roomName)s.": "<sender> changed the room name to %(roomName)s.",
+    "<sender> sent an image.": "<sender> sent an image.",
     "Someone": "Someone",
     "(not supported by this browser)": "(not supported by this browser)",
+    "<sender> answered the call.": "<sender> answered the call.",
     "(could not connect media)": "(could not connect media)",
     "(no answer)": "(no answer)",
     "(unknown failure: %(reason)s)": "(unknown failure: %(reason)s)",
+    "<sender> ended the call.": "<sender> ended the call.",
+    "<sender> placed a %(callType)s call.": "<sender> placed a %(callType)s call.",
+    "<sender> sent an invitation to %(targetDisplayName)s to join the room.": "<sender> sent an invitation to %(targetDisplayName)s to join the room.",
+    "<sender> made future room history visible to all room members, from the point they are invited.": "<sender> made future room history visible to all room members, from the point they are invited.",
+    "<sender> made future room history visible to all room members, from the point they joined.": "<sender> made future room history visible to all room members, from the point they joined.",
+    "<sender> made future room history visible to all room members.": "<sender> made future room history visible to all room members.",
+    "<sender> made future room history visible to anyone.": "<sender> made future room history visible to anyone.",
+    "<sender> made future room history visible to unknown (%(visibility)s).": "<sender> made future room history visible to unknown (%(visibility)s).",
+    "<sender> turned on end-to-end encryption (algorithm %(algorithm)s).": "<sender> turned on end-to-end encryption (algorithm %(algorithm)s).",
+    "<user> from %(fromPowerLevel)s to %(toPowerLevel)s": "<user> from %(fromPowerLevel)s to %(toPowerLevel)s",
+    "<sender> changed the power level of %(powerLevelDiffText)s.": "<sender> changed the power level of %(powerLevelDiffText)s.",
+    "<sender> changed the pinned messages for the room.": "<sender> changed the pinned messages for the room.",
+    "%(widgetName)s widget modified by <sender>": "%(widgetName)s widget modified by <sender>",
+    "%(widgetName)s widget added by <sender>": "%(widgetName)s widget added by <sender>",
+    "%(widgetName)s widget removed by <sender>": "%(widgetName)s widget removed by <sender>",
     "%(displayName)s is typing": "%(displayName)s is typing",
     "%(names)s and %(count)s others are typing|other": "%(names)s and %(count)s others are typing",
     "%(names)s and %(count)s others are typing|one": "%(names)s and one other is typing",
     "%(names)s and %(lastPerson)s are typing": "%(names)s and %(lastPerson)s are typing",
+    "Failure to create room": "Failure to create room",
+    "Server may be unavailable, overloaded, or you hit a bug.": "Server may be unavailable, overloaded, or you hit a bug.",
+    "Send anyway": "Send anyway",
+    "Send": "Send",
+    "Unnamed Room": "Unnamed Room",
     "Your browser does not support the required cryptography extensions": "Your browser does not support the required cryptography extensions",
     "Not a valid Riot keyfile": "Not a valid Riot keyfile",
     "Authentication check failed: incorrect password?": "Authentication check failed: incorrect password?",
@@ -277,29 +314,6 @@
     "Off": "Off",
     "On": "On",
     "Noisy": "Noisy",
-    "Invalid alias format": "Invalid alias format",
-    "'%(alias)s' is not a valid format for an alias": "'%(alias)s' is not a valid format for an alias",
-    "Invalid address format": "Invalid address format",
-    "'%(alias)s' is not a valid format for an address": "'%(alias)s' is not a valid format for an address",
-    "not specified": "not specified",
-    "not set": "not set",
-    "Remote addresses for this room:": "Remote addresses for this room:",
-    "Addresses": "Addresses",
-    "The main address for this room is": "The main address for this room is",
-    "Local addresses for this room:": "Local addresses for this room:",
-    "This room has no local addresses": "This room has no local addresses",
-    "New address (e.g. #foo:%(localDomain)s)": "New address (e.g. #foo:%(localDomain)s)",
-    "Invalid community ID": "Invalid community ID",
-    "'%(groupId)s' is not a valid community ID": "'%(groupId)s' is not a valid community ID",
-    "Flair": "Flair",
-    "Showing flair for these communities:": "Showing flair for these communities:",
-    "This room is not showing flair for any communities": "This room is not showing flair for any communities",
-    "New community ID (e.g. +foo:%(localDomain)s)": "New community ID (e.g. +foo:%(localDomain)s)",
-    "You have <a>enabled</a> URL previews by default.": "You have <a>enabled</a> URL previews by default.",
-    "You have <a>disabled</a> URL previews by default.": "You have <a>disabled</a> URL previews by default.",
-    "URL previews are enabled by default for participants in this room.": "URL previews are enabled by default for participants in this room.",
-    "URL previews are disabled by default for participants in this room.": "URL previews are disabled by default for participants in this room.",
-    "URL Previews": "URL Previews",
     "Cannot add any more widgets": "Cannot add any more widgets",
     "The maximum permitted number of widgets have already been added to this room.": "The maximum permitted number of widgets have already been added to this room.",
     "Add a widget": "Add a widget",
@@ -401,11 +415,11 @@
     "numbullet": "numbullet",
     "Markdown is disabled": "Markdown is disabled",
     "Markdown is enabled": "Markdown is enabled",
+    "Unpin Message": "Unpin Message",
+    "Jump to message": "Jump to message",
     "No pinned messages.": "No pinned messages.",
     "Loading...": "Loading...",
     "Pinned Messages": "Pinned Messages",
-    "Unpin Message": "Unpin Message",
-    "Jump to message": "Jump to message",
     "%(duration)ss": "%(duration)ss",
     "%(duration)sm": "%(duration)sm",
     "%(duration)sh": "%(duration)sh",
@@ -580,6 +594,9 @@
     "Invalid file%(extra)s": "Invalid file%(extra)s",
     "Error decrypting image": "Error decrypting image",
     "Error decrypting video": "Error decrypting video",
+    "%(senderDisplayName)s changed the avatar for %(roomName)s": "%(senderDisplayName)s changed the avatar for %(roomName)s",
+    "%(senderDisplayName)s removed the room avatar.": "%(senderDisplayName)s removed the room avatar.",
+    "%(senderDisplayName)s changed the room avatar to <img/>": "%(senderDisplayName)s changed the room avatar to <img/>",
     "Copied!": "Copied!",
     "Failed to copy": "Failed to copy",
     "Add an Integration": "Add an Integration",
@@ -755,7 +772,6 @@
     "Room directory": "Room directory",
     "Start chat": "Start chat",
     "And %(count)s more...|other": "And %(count)s more...",
-    "Share Link to User": "Share Link to User",
     "ex. @bob:example.com": "ex. @bob:example.com",
     "Add User": "Add User",
     "Matrix ID": "Matrix ID",
@@ -1193,44 +1209,5 @@
     "Import": "Import",
     "Failed to set direct chat tag": "Failed to set direct chat tag",
     "Failed to remove tag %(tagName)s from room": "Failed to remove tag %(tagName)s from room",
-    "Failed to add tag %(tagName)s to room": "Failed to add tag %(tagName)s to room",
-    "<target> accepted the invitation for %(displayName)s.": "<target> accepted the invitation for %(displayName)s.",
-    "<target> accepted an invitation.": "<target> accepted an invitation.",
-    "<sender> requested a VoIP conference.": "<sender> requested a VoIP conference.",
-    "<sender> invited <target>.": "<sender> invited <target>.",
-    "<sender> banned <target>.": "<sender> banned <target>.",
-    "<oldDisplayName> changed their display name to <displayName>.": "<oldDisplayName> changed their display name to <displayName>.",
-    "<sender> set their display name to <displayName>.": "<sender> set their display name to <displayName>.",
-    "<sender> removed their display name (<oldDisplayName>).": "<sender> removed their display name (<oldDisplayName>).",
-    "<sender> removed their profile picture.": "<sender> removed their profile picture.",
-    "<sender> changed their profile picture.": "<sender> changed their profile picture.",
-    "<sender> set a profile picture.": "<sender> set a profile picture.",
-    "<target> joined the room.": "<target> joined the room.",
-    "<target> rejected the invitation.": "<target> rejected the invitation.",
-    "<target> left the room.": "<target> left the room.",
-    "<sender> unbanned <target>.": "<sender> unbanned <target>.",
-    "<sender> kicked <target>.": "<sender> kicked <target>.",
-    "<sender> withdrew <target>'s invitation.": "<sender> withdrew <target>'s invitation.",
-    "<sender> changed the topic to \"%(topic)s\".": "<sender> changed the topic to \"%(topic)s\".",
-    "<sender> changed the room name to %(roomName)s.": "<sender> changed the room name to %(roomName)s.",
-    "<sender> changed the avatar for %(roomName)s": "<sender> changed the avatar for %(roomName)s",
-    "<sender> changed the room avatar to <img/>": "<sender> changed the room avatar to <img/>",
-    "<sender> removed the room name.": "<sender> removed the room name.",
-    "<sender> removed the room avatar.": "<sender> removed the room avatar.",
-    "<sender> answered the call.": "<sender> answered the call.",
-    "<sender> ended the call.": "<sender> ended the call.",
-    "<sender> placed a %(callType)s call.": "<sender> placed a %(callType)s call.",
-    "<sender> sent an invitation to %(targetDisplayName)s to join the room.": "<sender> sent an invitation to %(targetDisplayName)s to join the room.",
-    "<sender> made future room history visible to all room members, from the point they are invited.": "<sender> made future room history visible to all room members, from the point they are invited.",
-    "<sender> made future room history visible to all room members, from the point they joined.": "<sender> made future room history visible to all room members, from the point they joined.",
-    "<sender> made future room history visible to all room members.": "<sender> made future room history visible to all room members.",
-    "<sender> made future room history visible to anyone.": "<sender> made future room history visible to anyone.",
-    "<sender> made future room history visible to unknown (%(visibility)s).": "<sender> made future room history visible to unknown (%(visibility)s).",
-    "<sender> turned on end-to-end encryption (algorithm %(algorithm)s).": "<sender> turned on end-to-end encryption (algorithm %(algorithm)s).",
-    "<user> from %(fromPowerLevel)s to %(toPowerLevel)s": "<user> from %(fromPowerLevel)s to %(toPowerLevel)s",
-    "<sender> changed the power level of %(powerLevelDiffText)s.": "<sender> changed the power level of %(powerLevelDiffText)s.",
-    "<sender> changed the pinned messages for the room.": "<sender> changed the pinned messages for the room.",
-    "%(widgetName)s widget modified by <sender>": "%(widgetName)s widget modified by <sender>",
-    "%(widgetName)s widget added by <sender>": "%(widgetName)s widget added by <sender>",
-    "%(widgetName)s widget removed by <sender>": "%(widgetName)s widget removed by <sender>"
+    "Failed to add tag %(tagName)s to room": "Failed to add tag %(tagName)s to room"
 }
diff --git a/src/stores/RoomViewStore.js b/src/stores/RoomViewStore.js
index 35cfe69086..fed0d7b4a1 100644
--- a/src/stores/RoomViewStore.js
+++ b/src/stores/RoomViewStore.js
@@ -1,6 +1,6 @@
 /*
 Copyright 2017 Vector Creations Ltd
-Copyright 2017 New Vector Ltd
+Copyright 2017, 2018 New Vector Ltd
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
diff --git a/src/stores/WidgetEchoStore.js b/src/stores/WidgetEchoStore.js
new file mode 100644
index 0000000000..26d24c0563
--- /dev/null
+++ b/src/stores/WidgetEchoStore.js
@@ -0,0 +1,112 @@
+/*
+Copyright 2018 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import EventEmitter from 'events';
+
+import WidgetUtils from '../utils/WidgetUtils';
+import MatrixClientPeg from '../MatrixClientPeg';
+
+/**
+ * Acts as a place to get & set widget state, storing local echo state and
+ * proxying through state from the js-sdk.
+ */
+class WidgetEchoStore extends EventEmitter {
+    constructor() {
+        super();
+
+        this._roomWidgetEcho = {
+            // roomId: {
+            //     widgetId: [object]
+            // }
+        };
+    }
+
+    /**
+     * Gets the widgets for a room, substracting those that are pending deletion.
+     * Widgets that are pending addition are not included, since widgets are
+     * represted as MatrixEvents, so to do this we'd have to create fake MatrixEvents,
+     * and we don't really need the actual widget events anyway since we just want to
+     * show a spinner / prevent widgets being added twice.
+     */
+    getEchoedRoomWidgets(room, currentRoomWidgets) {
+        const echoedWidgets = [];
+
+        const roomEchoState = Object.assign({}, this._roomWidgetEcho[room.roomId]);
+
+        for (const w of currentRoomWidgets) {
+            const widgetId = w.getStateKey();
+            if (roomEchoState && roomEchoState[widgetId] && Object.keys(roomEchoState[widgetId]).length === 0) {
+                // delete locally so don't copy it
+            // we don't include widgets that have changed for the same rason we don't include new ones,
+            // so fall into the 'else' case and use the old one
+            //} else if (roomEchoState && roomEchoState[widgetId]) {
+            //    echoedWidgets.push(roomEchoState[widgetId]);
+            } else {
+                echoedWidgets.push(w);
+            }
+            delete roomEchoState[widgetId];
+        }
+
+        // any remining in roomEchoState are extra that need to be added
+        // We don't do this for the reasons above
+        /*for (const widgetId of Object.keys(roomEchoState)) {
+            echoedWidgets.push(roomEchoState[widgetId]);
+        }*/
+
+        return echoedWidgets;
+    }
+
+    roomHasPendingWidgetsOfType(room, currentRoomWidgets, type) {
+        const roomEchoState = Object.assign({}, this._roomWidgetEcho[room.roomId]);
+        if (roomEchoState === undefined) return false;
+
+        for (const w of currentRoomWidgets) {
+            const widgetId = w.getStateKey();
+            delete roomEchoState[widgetId];
+        }
+
+        if (type === undefined) {
+            return Object.keys(roomEchoState).length > 0;
+        } else {
+            return Object.values(roomEchoState).some((widget) => {
+                return widget.type === type; 
+            });
+        }
+    }
+
+    roomHasPendingWidgets(room, currentRoomWidgets) {
+        return this.roomHasPendingWidgetsOfType(room, currentRoomWidgets);
+    }
+
+    setRoomWidgetEcho(room, widgetId, state) {
+        if (this._roomWidgetEcho[room.roomId] === undefined) this._roomWidgetEcho[room.roomId] = {};
+
+        this._roomWidgetEcho[room.roomId][widgetId] = state;
+        this.emit('updateRoomWidgetEcho');
+    }
+
+    removeRoomWidgetEcho(room, widgetId) {
+        delete this._roomWidgetEcho[room.roomId][widgetId];
+        if (this._roomWidgetEcho[room.roomId] === {}) delete this._roomWidgetEcho[room.roomId];
+        this.emit('updateRoomWidgetEcho');
+    }
+}
+
+let singletonWidgetEchoStore = null;
+if (!singletonWidgetEchoStore) {
+    singletonWidgetEchoStore = new WidgetEchoStore();
+}
+module.exports = singletonWidgetEchoStore;
diff --git a/src/utils/WidgetUtils.js b/src/utils/WidgetUtils.js
index ab5b5b0130..43ca20e886 100644
--- a/src/utils/WidgetUtils.js
+++ b/src/utils/WidgetUtils.js
@@ -19,6 +19,7 @@ import MatrixClientPeg from '../MatrixClientPeg';
 import SdkConfig from "../SdkConfig";
 import dis from '../dispatcher';
 import * as url from "url";
+import WidgetEchoStore from '../stores/WidgetEchoStore';
 
 export default class WidgetUtils {
     /* Returns true if user is able to send state events to modify widgets in this room
@@ -250,11 +251,16 @@ export default class WidgetUtils {
             content = {};
         }
 
+        const room = MatrixClientPeg.get().getRoom(roomId);
+        WidgetEchoStore.setRoomWidgetEcho(room, widgetId, content);
+
         const client = MatrixClientPeg.get();
         // TODO - Room widgets need to be moved to 'm.widget' state events
         // https://docs.google.com/document/d/1uPF7XWY_dXTKVKV7jZQ2KmsI19wn9-kFRgQ1tFQP7wQ/edit?usp=sharing
         return client.sendStateEvent(roomId, "im.vector.modular.widgets", content, widgetId).then(() => {
             return WidgetUtils.waitForRoomWidget(widgetId, roomId, addingWidget);
+        }).finally(() => {
+            WidgetEchoStore.removeRoomWidgetEcho(room, widgetId);
         });
     }