Just some clarifications to the instructions provided in this article. Hopefully, it will save you time to get you up and running faster. 1) Nifi 401:Unauthorized Error If you see a similar error message in the Nifi console: ERROR [Timer-Driven Process Thread-6] o.a.nifi.processors.standard.PostHTTP PostHTTP[id=834bb9f9-a15d-42bd-8d7a-3f00c810d729] Failed to Post StandardFlowFileRecord[uuid=bc74e1c5-12e7-4da2-93b4-a3dc624218ac,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1471370511531-1, container=default, section=1], offset=11780, length=407],offset=0,name=12406098021784,size=407] to http://gcm-http.googleapis.com/gcm/send: response code was 401:Unauthorized and when you click "Notify Customer" in the Analyst's console and no event is updated on the Android emulator in Android Studio. Resolution 401:Unauthorized Error Open open the UpdateAttribute processor and add a new property called Authorization and set its value to key=your google browser key 2) Wrong Google API number The API project number is 12 digits. Do not use the number at the end of the Google API Project ID. For example, ID: api-project-555555555 Resolution Google API number Use the number given in the Google API console at Project Number (see screenshot below). This will to successfully link from the Sandbox to the mobile emulator; otherwise, you'll click "Notify Customer" in the Analyst's console and no event is updated on the Android emulator in Android Studio. 3) Mobile Application Compilation FYI I thought it helps to provide and example to this section of the Readme because it severely edits the XML syntax. Under the res folder, browse to: app-->res-->values-->google_maps_api.xml (debug): string name="google_maps_key" templateMergeStrategy="preserve" translatable="false" ENTER YOUR GOOGLE BROWSER KEY CREDENTIAL HERE /string Here's what it looks like in Android Studio with xml syntax preserved shown in green box below between "><" identifying the string. Hope this helps! ... View more