Does anyone know whether UNA has a default URL scheme built into the mobile apps?

I ask because when dealing with social logins (Twitter specifically) in the mobile app, when trying to login with Twitter, it kicks out to the external browser and then gets stuck there in a blank page and when force switching back to the app it does not pass the token for login. I think if there was a scheme:// URI used vice https:// URI it should kick back to the app on its own with the token.

Any thoughts?