diff --git a/dom/apps/Webapps.js b/dom/apps/Webapps.js
index 0d3c6c361704..ee06bd30e74e 100644
--- a/dom/apps/Webapps.js
+++ b/dom/apps/Webapps.js
@@ -748,6 +748,7 @@ WebappsApplicationMgmt.prototype = {
                                         "Webapps:Uninstall:Return:KO",
                                         "Webapps:Install:Return:OK",
                                         "Webapps:GetNotInstalled:Return:OK",
+                                        "Webapps:GetIcon:Return",
                                         "Webapps:Import:Return",
                                         "Webapps:ExtractManifest:Return",
                                         "Webapps:SetEnabled:Return"]);
@@ -813,6 +814,21 @@ WebappsApplicationMgmt.prototype = {
     return request;
   },
 
+  getIcon: function(aApp, aIconID, aEntryPoint) {
+    return this.createPromise(function(aResolve, aReject) {
+      cpmm.sendAsyncMessage("Webapps:GetIcon", {
+        oid: this._id,
+        manifestURL: aApp.manifestURL,
+        iconID: aIconID,
+        entryPoint: aEntryPoint,
+        requestID: this.getPromiseResolverId({
+          resolve: aResolve,
+          reject: aReject
+        })
+      });
+    }.bind(this));
+  },
+
   getNotInstalled: function() {
     let request = this.createRequest();
     let principal = this._window.document.nodePrincipal;
@@ -887,7 +903,8 @@ WebappsApplicationMgmt.prototype = {
     let msg = aMessage.data;
     let req;
 
-    if (["Webapps:Import:Return",
+    if (["Webapps:GetIcon:Return",
+         "Webapps:Import:Return",
          "Webapps:ExtractManifest:Return"]
          .indexOf(aMessage.name) != -1) {
       req = this.takePromiseResolver(msg.requestID);
@@ -953,7 +970,18 @@ WebappsApplicationMgmt.prototype = {
           this.__DOM_IMPL__.dispatchEvent(event);
         }
         break;
+      case "Webapps:GetIcon:Return":
+        if (msg.blob) {
+          req.resolve(Cu.cloneInto(msg.blob, this._window));
+        } else if (msg.error && msg.error == "NETWORK_ERROR"
+                             && !this._window.navigator.onLine) {
+          req.reject(new this._window.DOMError("NETWORK_OFFLINE"));
+        } else {
+          req.reject(new this._window.DOMError(msg.error || ""));
+        }
+        break;
     }
+
     if (aMessage.name !== "Webapps:Uninstall:Broadcast:Return:OK") {
       this.removeRequest(msg.requestID);
     }
diff --git a/dom/apps/Webapps.jsm b/dom/apps/Webapps.jsm
index 432dfb3adb8d..c48fa1e0b22c 100755
--- a/dom/apps/Webapps.jsm
+++ b/dom/apps/Webapps.jsm
@@ -221,6 +221,7 @@ this.DOMApplicationRegistry = {
                      "Webapps:RegisterBEP",
                      "Webapps:Export",
                      "Webapps:Import",
+                     "Webapps:GetIcon",
                      "Webapps:ExtractManifest",
                      "Webapps:SetEnabled",
                      "child-process-shutdown"];
@@ -1405,6 +1406,9 @@ this.DOMApplicationRegistry = {
         case "Webapps:RegisterBEP":
           this.registerBrowserElementParentForApp(msg, mm);
           break;
+        case "Webapps:GetIcon":
+          this.getIcon(msg, mm);
+          break;
         case "Webapps:Export":
           this.doExport(msg, mm);
           break;
@@ -4213,6 +4217,74 @@ this.DOMApplicationRegistry = {
     });
   },
 
+  getIcon: function(aData, aMm) {
+    function sendError(aError) {
+      debug("getIcon error: " + aError);
+      aData.error = aError;
+      aMm.sendAsyncMessage("Webapps:GetIcon:Return", aData);
+    }
+
+    let app = this.getAppByManifestURL(aData.manifestURL);
+    if (!app) {
+      sendError("NO_APP");
+      return;
+    }
+
+    function loadIcon(aUrl) {
+      let fallbackMimeType = aUrl.indexOf('.') >= 0 ?
+                             "image/" + aUrl.split(".").reverse()[0] : "";
+      // Set up an xhr to download a blob.
+      let xhr = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
+                  .createInstance(Ci.nsIXMLHttpRequest);
+      xhr.mozBackgroundRequest = true;
+      xhr.open("GET", aUrl, true);
+      xhr.responseType = "blob";
+      xhr.addEventListener("load", function() {
+        debug("Got http status=" + xhr.status + " for " + aUrl);
+        if (xhr.status == 200) {
+          let blob = xhr.response;
+          // Reusing aData with sendAsyncMessage() leads to an empty blob in
+          // the child.
+          let payload = {
+            "oid": aData.oid,
+            "requestID": aData.requestID,
+            "blob": blob,
+            "type": xhr.getResponseHeader("Content-Type") || fallbackMimeType
+          };
+          aMm.sendAsyncMessage("Webapps:GetIcon:Return", payload);
+        } else if (xhr.status === 0) {
+          sendError("NETWORK_ERROR");
+        } else {
+          sendError("FETCH_ICON_FAILED");
+        }
+      });
+      xhr.addEventListener("error", function() {
+        sendError("FETCH_ICON_FAILED");
+      });
+      xhr.send();
+    }
+
+    // Get the manifest, to find the icon url in the current locale.
+    this.getManifestFor(aData.manifestURL, aData.entryPoint)
+        .then((aManifest) => {
+      if (!aManifest) {
+        sendError("FETCH_ICON_FAILED");
+        return;
+      }
+
+      let manifest = new ManifestHelper(aManifest, app.origin, app.manifestURL);
+      let url = manifest.iconURLForSize(aData.iconID);
+      if (!url) {
+        sendError("NO_ICON");
+        return;
+      }
+      loadIcon(url);
+    }).catch(() => {
+      sendError("FETCH_ICON_FAILED");
+      return;
+    });
+  },
+
   getAll: function(aCallback) {
     debug("getAll");
     let apps = [];
@@ -4446,7 +4518,7 @@ this.DOMApplicationRegistry = {
     });
   },
 
-  getManifestFor: function(aManifestURL) {
+  getManifestFor: function(aManifestURL, aEntryPoint) {
     let id = this._appIdForManifestURL(aManifestURL);
     let app = this.webapps[id];
     if (!id || (app.installState == "pending" && !app.retryingDownload)) {
@@ -4454,7 +4526,11 @@ this.DOMApplicationRegistry = {
     }
 
     return this._readManifests([{ id: id }]).then((aResult) => {
-      return aResult[0].manifest;
+      if (aEntryPoint) {
+        return aResult[0].manifest.entry_points[aEntryPoint];
+      } else {
+        return aResult[0].manifest;
+      }
     });
   },
 
diff --git a/dom/webidl/Apps.webidl b/dom/webidl/Apps.webidl
index 212ac8a415ec..b1180e262730 100644
--- a/dom/webidl/Apps.webidl
+++ b/dom/webidl/Apps.webidl
@@ -98,6 +98,8 @@ interface DOMApplicationsManager : EventTarget {
   Promise<any> extractManifest(Blob blob);
 
   void setEnabled(DOMApplication app, boolean state);
+  Promise<Blob> getIcon(DOMApplication app, DOMString iconID,
+                        optional DOMString entryPoint);
 
   attribute EventHandler oninstall;
   attribute EventHandler onuninstall;