
                    For onesignal, we pick up the best solutions provided by github life savers.
                    If google brings you here, you are so lucky! These life savers are angels, they have well solved your problems.
                    So do not waste time scrolling the original issue threads just to dig out solutions... 
                    Here you are, you are welcome. Then, go back to work!
                    

Try to declare onesignal-gradle-plugin before google-services in android\app\build.gradle:
apply plugin: 'com.onesignal.androidsdk.onesignal-gradle-plugin'
apply plugin: 'com.google.gms.google-services'

react native onesignal a resolved Google Play services library dependency depends on another at an exact version (e.g. "[10.2.   1, 16.0.99]", but isn't being resolved to that version.

Can you try pod update? Hello I have problem installing this library 

react native onesignal IOS pod install is failing

@rodrigofbm In your android/build.gradle in your repositories section try moving google() ABOVE jcenter() It's bizarre 

react native onesignal Could not find firebase-iid.aar...

Update 2018-11-07
This looks to be conflict with another plugin including a different interdependency of the Google Play services library 

react native onesignal com.android.dex.DexException: Multiple dex files define Lcom/google/android/gms/internal/zzas;

Went through this exact same issue and like @indapublic did I had added the extension to my Podfile incorrectly Just wanted to add some clarity 

react native onesignal OneSignalNotificationServiceExtension causes sharedApplication build issues

@brunoandradebr @DaniloCouto @ifanfaizal  I fix Description:
The registred device returns an error on OneSignal dashboard 

react native onesignal Google Play Services Library Error

I had same problem and just removed the following lines from package.json in node_modules/react-native-onesignal and apparently my problem with android is now solved :

react native onesignal Not working on React Native 0.60

The goal was to recieve PlayerID from Onesignal on application launch So in App.js for me worked the following code: 

react native onesignal Get the current playerid/userid

Turns out react-native link did not work correctly as usual :D I just had to manually add the RCTOneSignal project into Libraries and then I was able to add libRCTOneSignal.a
I think it would be nice if you guys can add the instructions for manually linking in addition to react-native link so people can verify if link worked correctly :)

react native onesignal Unable to find libRCTOneSignal.a

For now Description:
When calling OneSignal.init() in Android the app crashes with the error Java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.reactnativeprototype

react native onesignal (3.2.3) Android app crashes with Java.lang.IllegalStateException: Default FirebaseApp is not initialized in this process com.{appname}. Make sure to call FirebaseApp.initializeApp(Context) first when calling init()

I’m having some issues too with Xcode 12
I can successfully build the project on Xcode 11 

react native onesignal OneSignal OneSignalNotificationExtension build fail on Xcode 12 related to cocoapods / architecture / simulator issues

@jdegger that approach seems to have worked for me also Description:
On iOS I am able to setup the SDK to work with notifications however 

react native onesignal Unable to add Notification Service Extension

@dwilt @Ouadie As of version 3.0.3 the OneSignal iOS native SDK is now part of it You will need to remove  the Cocoapod Carthage 