Pokémon GO is in the process of being updated to version 0.83.1 for Android and 1.53.2 for iOS devices. Details from our development team:
- Added support and made optimizations for the iPhone X screen resolution.
- Removed support for devices running iOS 8.
- Resolved a bug causing error banners to remain visible until the app is restarted.
- Resolved a bug that prevented Trainers from powering up Pokémon to their max CP.
- Improved load times when you open the app.
- Various bug fixes and performance updates.
—The Pokémon GO team