What is your favourite app on Iphone?

Tell me your favourite free app or game on iphone and please don't mention famous apps such as twitter or facebook and so on. You can mention more than one app If you want to, and what is the app that takes a picture from the front camera when some one tries to enter the password and enters it wrong… Thanks.

Temple run: D

Dubblen! You can create the coolest pictures - two of you in one picture!

I love fun apps. There are number of apps installed in my iPhone such as Major Mayham, Where's my Water, Bingo Bash, Tap tap Revenge tour etc. But the latest versions of iTazer, Subway Surfer and Temple Run are my favorite apps. Because it contains lots of fun and amazing graphics designs. I got these apps from my cousin's suggested web-link
http://www.redsn0w-download.com/
http://www.itazer.com/.