1) iStudiez Pro. Junior year means homework/projects out the *** and this app saved me more then once.
2) Human Japanese. I've been wanting to learn Japanese for the longest but never had time to take the class, and this app helps a lot. I was learning the language faster then my roommate who was learning the course. It's a good way to learn until i actually take the class
3) TFLN. This is easily my most used app. Nothing lightens my day up faster then reading some of the most random/ craziest texts off this site. This could be replaced by FML too, bc before i downloaded this app, FML was the most used.
4) Yellow Pages. This app saved my *** about as much as iStudiez Pro has. Definitely my most important app, since i seem to constantly be looking for something like the closest store
As you can tell, i don't use none of the game apps much (ps3 + 360 +hdtv + little time = no going to iphone for games).