I strongly suggest the Plan B app, mainly for the text-to-activate GPS email locator. So if my phone is lost/stolen, I can get a rough idea where it's at, within 90 feet. It would be stupid not to have an app like this installed on your phone, since they cost $200+
I don't really use any other apps.
I had a threesome last night, there were a couple of no shows but I still had a good time!
Facebook, FB Messenger, Super Sudoku, System Tuner, Paper Camera, Can Knockdown, Paper Toss, Google Sky Map, Pulse, ebay, Speed Test, Shazam, Soundhound, MX Video Player, Video Downloader, Zedge, Pano and maybe a few others.