100 Doors is a puzzle android app from MPI games. Your objective to open the door in each level by solving clever puzzles. By the way this app is often mistaken for another app called 100 Floors - its a different app. Anyways, what I have here is a guide showing solutions to different levels of the game. I searched the web high and low to come with this walkthrough and so far this what we've got (we'll try to update soon - this very difficult so if you got some tips, please share with us).
100 Doors walkthrough