First issues, on the initial sign in screen:
- Text overflows box (see highlighted area in picture)
- There is no indication of what to do after you put something in the box. The login button is over to the right, hidden.
- Why is there a list of permissions? It's the official app, not a third-party app.
Then, after going through the provider, you come back to another screen. Why is the list of permissions here again? Already showed it once. It'd probably be better to only have it here, so that you could get the login button visible on the first screen.