Which RT-Apps Make your Lives Easier?

Hey guys,

I'm curious to hear which apps enhance your lives and in what way.

I've read about people using their iPads for presentations, scheduling, music production and recording, as a teacher's aid, or simply as an 800 € facebook machine.

So which apps that you use

- are the prettiest?
- save you the most time?
- are simply useful?
- surprising in any way?
- don't get in the way?

Thanks guys!