Don't know if it's just me but turning off the sound in "Settings" makes the app quit.  Also the chat feature failed with an error message saying "try again later" or some such...  Lastly, the listing of videos is truncated so you can't distinguish which ones you've previously seen.  For instance, every one of the 10 videos titled "Rook Engames: Beginner to Master, Part 1, 2, 3..." appears as "Rook Endgames: Beginner..." with no way to expand the title, just an option to play it.

these are minor and I'm sure will get fixed somehow later... all in all, an amazing app.

yes my app keeps quiting for no reason???

Both of you, please see this thread : http://www.chess.com/forum/view/help-support/iphone-bugs