Patatap is a very cool sound app! You can get ported versions for mobile in the App Store & on Google Play, but I’ve only tried the browser version at http://www.patatap.com/ . Highly amusing, best paired with recreational intoxicants (Caesar-with-pickle highly recommended). Cost me hours of productive time.
I’m a huge nerd with a terrible procrastination habit. I surf aimlessly for hours. Wikipedia is the best, most awesome thing ever (and it provided ~70% of my university education). Visit http://listen.hatnote.com/ for a lovely sonic realization of Wikipedia’s recent changes (including new users, edits, & newly created articles). Gorgeous.