diff --git a/src/UserSettingsStore.js b/src/UserSettingsStore.js
index 68a1ba229f..1d1924cd23 100644
--- a/src/UserSettingsStore.js
+++ b/src/UserSettingsStore.js
@@ -33,11 +33,17 @@ export default {
             // XXX: Always use default, ignore localStorage and remove from labs
             override: true,
         },
+        {
+            name: "-",
+            id: 'feature_flair',
+            default: false,
+        },
     ],
 
     // horrible but it works. The locality makes this somewhat more palatable.
     doTranslations: function() {
         this.LABS_FEATURES[0].name = _t("Matrix Apps");
+        this.LABS_FEATURES[1].name = _t("Flair");
     },
 
     loadProfileInfo: function() {
diff --git a/src/components/views/elements/Flair.js b/src/components/views/elements/Flair.js
new file mode 100644
index 0000000000..6c32933faf
--- /dev/null
+++ b/src/components/views/elements/Flair.js
@@ -0,0 +1,209 @@
+/*
+ Copyright 2017 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.
+ */
+
+'use strict';
+
+import React from 'react';
+import PropTypes from 'prop-types';
+import {MatrixClient} from 'matrix-js-sdk';
+import UserSettingsStore from '../../../UserSettingsStore';
+
+const BULK_REQUEST_DEBOUNCE_MS = 200;
+
+// Does the server support groups? Assume yes until we receive M_UNRECOGNIZED.
+// If true, flair can function and we should keep sending requests for groups and avatars.
+let groupSupport = true;
+
+// TODO: Cache-busting based on time. (The server won't inform us of membership changes.)
+// This applies to userGroups and groupProfiles. We can provide a slightly better UX by
+// cache-busting when the current user joins/leaves a group.
+const userGroups = {
+    // $userId: ['+group1:domain', '+group2:domain', ...]
+};
+
+const groupProfiles = {
+//  $groupId: {
+//      avatar_url: 'mxc://...'
+//  }
+};
+
+// Represents all unsettled promises to retrieve the groups for each userId. When a promise
+// is settled, it is deleted from this object.
+const usersPending = {
+//  $userId: {
+//      prom: Promise
+//      resolve: () => {}
+//      reject: () => {}
+//  }
+};
+
+let debounceTimeoutID;
+function getPublicisedGroupsCached(matrixClient, userId) {
+    if (userGroups[userId]) {
+        return Promise.resolve(userGroups[userId]);
+    }
+
+    // Bulk lookup ongoing, return promise to resolve/reject
+    if (usersPending[userId]) {
+        return usersPending[userId].prom;
+    }
+
+    usersPending[userId] = {};
+    usersPending[userId].prom = new Promise((resolve, reject) => {
+        usersPending[userId].resolve = resolve;
+        usersPending[userId].reject = reject;
+    }).then((groups) => {
+        userGroups[userId] = groups;
+        // TODO: Reset cache at this point
+        return userGroups[userId];
+    }).catch((err) => {
+        throw err;
+    }).finally(() => {
+        delete usersPending[userId];
+    });
+
+    // This debounce will allow consecutive requests for the public groups of users that
+    // are sent in intervals of < BULK_REQUEST_DEBOUNCE_MS to be batched and only requested
+    // when no more requests are received within the next BULK_REQUEST_DEBOUNCE_MS. The naive
+    // implementation would do a request that only requested the groups for `userId`, leading
+    // to a worst and best case of 1 user per request. This implementation's worst is still
+    // 1 user per request but only if the requests are > BULK_REQUEST_DEBOUNCE_MS apart and the
+    // best case is N users per request.
+    //
+    // This is to reduce the number of requests made whilst trading off latency when viewing
+    // a Flair component.
+    if (debounceTimeoutID) clearTimeout(debounceTimeoutID);
+    debounceTimeoutID = setTimeout(() => {
+        batchedGetPublicGroups(matrixClient);
+    }, BULK_REQUEST_DEBOUNCE_MS);
+
+    return usersPending[userId].prom;
+}
+
+async function batchedGetPublicGroups(matrixClient) {
+    // Take the userIds from the keys of usersPending
+    const usersInFlight = Object.keys(usersPending);
+    let resp = {
+        users: [],
+    };
+    try {
+        resp = await matrixClient.getPublicisedGroups(usersInFlight);
+    } catch (err) {
+        // Propagate the same error to all usersInFlight
+        usersInFlight.forEach((userId) => {
+            usersPending[userId].reject(err);
+        });
+        return;
+    }
+    const updatedUserGroups = resp.users;
+    usersInFlight.forEach((userId) => {
+        usersPending[userId].resolve(updatedUserGroups[userId] || []);
+    });
+}
+
+async function getGroupProfileCached(matrixClient, groupId) {
+    if (groupProfiles[groupId]) {
+        return groupProfiles[groupId];
+    }
+
+    groupProfiles[groupId] = await matrixClient.getGroupProfile(groupId);
+    return groupProfiles[groupId];
+}
+
+export default class Flair extends React.Component {
+    constructor() {
+        super();
+        this.state = {
+            avatarUrls: [],
+        };
+    }
+
+    componentWillUnmount() {
+        this._unmounted = true;
+    }
+
+    componentWillMount() {
+        this._unmounted = false;
+        if (UserSettingsStore.isFeatureEnabled('feature_flair') && groupSupport) {
+            this._generateAvatars();
+        }
+    }
+
+    async _getAvatarUrls(groups) {
+        const profiles = [];
+        for (const groupId of groups) {
+            let groupProfile = null;
+            try {
+                groupProfile = await getGroupProfileCached(this.context.matrixClient, groupId);
+            } catch (err) {
+                console.error('Could not get profile for group', groupId, err);
+            }
+            profiles.push(groupProfile);
+        }
+
+        const avatarUrls = profiles.filter((p) => p !== null).map((p) => p.avatar_url);
+        return avatarUrls;
+    }
+
+    async _generateAvatars() {
+        let groups;
+        try {
+            groups = await getPublicisedGroupsCached(this.context.matrixClient, this.props.userId);
+        } catch (err) {
+            // Indicate whether the homeserver supports groups
+            if (err.errcode === 'M_UNRECOGNIZED') {
+                console.warn('Cannot display flair, server does not support groups');
+                groupSupport = false;
+                // Return silently to avoid spamming for non-supporting servers
+                return;
+            }
+            console.error('Could not get groups for user', this.props.userId, err);
+        }
+        if (!groups || groups.length === 0) {
+            return;
+        }
+        const avatarUrls = await this._getAvatarUrls(groups);
+        if (!this.unmounted) {
+            this.setState({avatarUrls});
+        }
+    }
+
+    render() {
+        if (this.state.avatarUrls.length === 0) {
+            return <div />;
+        }
+        const avatars = this.state.avatarUrls.map((avatarUrl, index) => {
+            const httpUrl = this.context.matrixClient.mxcUrlToHttp(avatarUrl, 14, 14, 'scale', false);
+            return <img key={index} src={httpUrl} width="14px" height="14px"/>;
+        });
+        return (
+            <span className="mx_Flair" style={{"marginLeft": "5px", "verticalAlign": "-3px"}}>
+                {avatars}
+            </span>
+        );
+    }
+}
+
+Flair.propTypes = {
+    userId: PropTypes.string,
+};
+
+// TODO: We've decided that all components should follow this pattern, which means removing withMatrixClient and using
+// this.context.matrixClient everywhere instead of this.props.matrixClient.
+// See https://github.com/vector-im/riot-web/issues/4951.
+Flair.contextTypes = {
+    matrixClient: React.PropTypes.instanceOf(MatrixClient).isRequired,
+};
diff --git a/src/components/views/messages/SenderProfile.js b/src/components/views/messages/SenderProfile.js
index e224714a27..e9d2fe62ff 100644
--- a/src/components/views/messages/SenderProfile.js
+++ b/src/components/views/messages/SenderProfile.js
@@ -18,6 +18,7 @@
 
 import React from 'react';
 import sdk from '../../../index';
+import Flair from '../elements/Flair.js';
 
 export default function SenderProfile(props) {
     const EmojiText = sdk.getComponent('elements.EmojiText');
@@ -30,8 +31,11 @@ export default function SenderProfile(props) {
     }
 
     return (
-        <EmojiText className="mx_SenderProfile" dir="auto"
-              onClick={props.onClick}>{`${name || ''} ${props.aux || ''}`}</EmojiText>
+        <div className="mx_SenderProfile" dir="auto" onClick={props.onClick}>
+            <EmojiText>{name || ''}</EmojiText>
+            {props.enableFlair ? <Flair userId={mxEvent.getSender()} /> : null}
+            {props.aux ? <EmojiText> props.aux</EmojiText> : null}
+        </div>
     );
 }
 
diff --git a/src/components/views/rooms/EventTile.js b/src/components/views/rooms/EventTile.js
index a6f8ed5542..7328cfe0b6 100644
--- a/src/components/views/rooms/EventTile.js
+++ b/src/components/views/rooms/EventTile.js
@@ -508,10 +508,10 @@ module.exports = withMatrixClient(React.createClass({
                 if (msgtype === 'm.image') aux = _t('sent an image');
                 else if (msgtype === 'm.video') aux = _t('sent a video');
                 else if (msgtype === 'm.file') aux = _t('uploaded a file');
-                sender = <SenderProfile onClick={ this.onSenderProfileClick } mxEvent={this.props.mxEvent} aux={aux} />;
+                sender = <SenderProfile onClick={ this.onSenderProfileClick } mxEvent={this.props.mxEvent} enableFlair={!aux} aux={aux} />;
             }
             else {
-                sender = <SenderProfile mxEvent={this.props.mxEvent} />;
+                sender = <SenderProfile mxEvent={this.props.mxEvent} enableFlair={true} />;
             }
         }
 
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 747f8100ad..464ab63683 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -883,5 +883,8 @@
     "Failed to invite users to %(groupId)s": "Failed to invite users to %(groupId)s",
     "Unable to reject invite": "Unable to reject invite",
     "Leave Group": "Leave Group",
-    "Leave %(groupName)s?": "Leave %(groupName)s?"
+    "Leave %(groupName)s?": "Leave %(groupName)s?",
+    "%(widgetName)s widget modified by %(senderName)s": "%(widgetName)s widget modified by %(senderName)s",
+    "Robot check is currently unavailable on desktop - please use a <a>web browser</a>": "Robot check is currently unavailable on desktop - please use a <a>web browser</a>",
+    "Flair": "Flair"
 }