Apparently someone has finally done it, which uses Niantic's API. It shows where pokemon are, and how long they will be there for.
Kind of takes the fun out of the game, but if you're desperate or want to catch up to some of your friends... try it out.
Article: http://lifehacker.com/pokevision-shows-you-the-real-time-locations-of-pokemon-1784061259
Site: https://pokevision.com/
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