I recently downloaded the game and have been experiencing an issue where at the end of a game that I don't win, the 5 More Moves buying screen pops up and processes (because I can't see it) but without any visual graphics to indicate anything happened.
I ended up accidentally spending 88 gems on it in that manner without even knowing it and the only REASON I noticed is because the next time it happened, I didn't have enough Gems and so it prompted a different pop-up which then triggered the original Buy 5 Moves screen AND visual graphics to become visible.
That said, I'm not terribly happy about the fact that something like that can process when I can't even see the visuals on the screen.
iPod Touch 5th Gen, iOS 7.1