What is your fave mobile app? Im quitting fb, twitter and tumblr and looking for apps to replace them. They make me very depressed and I waste too much time on them.

Any suggestions? I like animals and nature, music, literature, world leaders/influencers, and science. I like people like Jane Goodall, Steve Irwin, Bill Nye, Neil DeGrasse Tyson, Stephen Hawking...i also like musicians like Rob Thomas, blues, classic rock. I am also interested in apps about self discovery, meditation, positive thinking, etc.