I am using https://github.com/cgisca/PGSGP.
It took two weeks to get this plug-in working in my game. The biggest challenge was getting the project set-up correctly on the Google Play Developer Console, Google Game Play Console, and Google APIs and Services. Frankly, I think Google makes it difficult to set-up just so they don't get a bunch of junk apps in the Play Store.
I finally got it working by doing the following. First, follow the instructions in the plug-in README. Take note of the following if you are using other plug-ins in your game such as an AdMob plugin:
*Note 2: If you have already added other plugin that has meta-data android:name="com.google.android.gms.version" declared inside it's AndroidManifest, remove below lines from the android-pgs-plugin-> AndroidManifest.conf file. (Don't forget to save file after removing below lines)
Also, you have to add the following two lines to res://android/build/gradle.properties:
Next, be sure to add the following APIs to your project in Google APIs & Services Console:
- Google Game Play Services
- Google Play Game Management
- Google Drive API
I was missing the Google Drive API which caused an error code 8 ("Internal Failure") return from the sign-in call. It was frustrating because there are no clues to what is failing. There is nothing in the README that identifies the Drive API is needed. I finally found a clue in the Corona forums for a similar plug-in.