If you have issues with the setup (the app is blocked or SMS permission is denied), you can now install a version of the app directly from Google Play.
Get It On Google PlayOn some devices Google will identify the app as harmful (since it needs SMS access). Click the install anyway option.
On some devices SMS permission will be blocked. If you see the message below, you need to turn on "Allow restricted settings".
Open the phone's App info screen for the app and turn on the "Allow restricted settings" option.
Restart the app, or manually allow the SMS permission.