I´ve implemented the Google and Facebook login manually, but the login buttons look differently so I was looking for a more convenient way to implement it.
There seems to be the AuthUI.getInstance().createSignInIntentBuilder() which seems to be deprecated. The JavaDoc says
@deprecated this constant is no longer needed, use the {@link IdpConfig.FacebookBuilder}
So I´ve looked up the Google Identity Toolkit, but that seems to be out of development since 2013, at least according to this Github Repository
https://github.com/googlesamples/identity-toolkit-android
Is there some common way to do it nowadays except from doing the button layouts manually to make them equal?