Improved distribution of game difficulty across levels
Pawn promotion is now fully implemented, allowing the player to choose the desired piece
Fixed a rare issue where repeated “illegal move” error alerts could appear and not clear properly
Support for Dark Mode added
New app icon

This update fixes the following problems:
- Occasional illegal first move by computer when computer plays white
- Infrequent hanging of "Illegal move" warning
Mac version of the game is updated, too

- General update for iOS v.14
- Enhancements in the AI of the game
- Indication of the current difficulty level
- Show error when putting the king in check or for some other wrong moves (optionally)
- A few other minor issues

Various chess board appearances

- GUI improvements
- Grandmaster difficulty level (in full version)
- Multiple board types (in full version)