A lot or a little?
Parents need to know that Deck 'Em! is a card-based fighting game for iOS devices. While it's a fighting game, you don't actually see anyone fighting, though you do see the aftermath, including black eyes and other abrasions. Otherwise, though, it has no objectionable content. Players earn in-game money by playing, and this money can be used to bet on upcoming bouts. Players can also give tips of $2.99 or $9.99 to the developers, though it doesn't give them anything in return. Read the developer's privacy policy for details on how your (or your kids') information is collected, used, and shared, and any choices you may have in the matter, and note that privacy policies and terms of service frequently change.