Camera App - I don't know how many times this one's be there for me, I recommend this it's really handy !
Voice Recorder - With this app employed 24/7, it'll make you immune to false allegations from those crazies who call the police of you over nothing. Good for stuff.
Music - So many of these to choose from, but this one's called Music, and it plays mp3's. Like the other useful apps, it came installed and ready to rip.
Clock - It's calibrated to an atomic clock through the networks for razor sharp accuracy, the clock app however can do the alarm clock, world clock, stopwatch, and timer thing.
Flash Light - Dropped something in the bushes in the middle of the night and need a flashlight ? If your phone is good enough, it has an LED built in, and you still had to download the damn app to use it like this.
facebook app - Not as useful, but you're using it anyway.
Whatsapp - Not everyone uses this, and maybe not everyone will. But for the rest of us who do, we enjoy internet based long distance phone calls. You use prepaid long distance services, or you just make the call and get the stupid bill. Me, I just use whatsapp.
RealCalc Scientific Calculator - Cause life will at times slap you with a bunch of numbers and using a calculator is better than a pencil and paper. This app turns your mobile device into one of those expensive scientific calculators for free.
UTorrent app - Thou shall share music movies and software such as.apk files.
Easy.