It's interesting that this topic was started a few months back.
The Apple App market is in full run again. The announcement of iOS 7 has sent developers on their feet. It's going to be interesting to see what's popular now.
Now a days I am using lot of apps but some are here Photoshop Fix, Uber, snapchat, cash and some games i.e. PKT ball, sparkwave, looty dungeon and many more.
I have games like Stack, PVZ2, Color Switch, Four Letters, Turn, and O2Jam U installed on my iPad. I also have teacher-essential apps like Teacher Kit to help me with my grade recordings in class. I have also installed Word, Powerpoint, and Excel.