The app works ok but the experience outside the app is the problem. You can log in with Google inside the app but on the GroupMe website you can't, you have to use email + password that you may have never created. If you have a link to a GroupMe you can't open it with the app, you have to open it in the browser, if you originally made your GroupMe with the Google sign in you have to "change" your password to then log in to join the group. The group might not show up so you have to relogin also.