PhotoCreds:Google

Even though Flappy bird didn't gain popularity until Mid January, the game was released in early June. It is amazing how a game can be kept silent and then it blows up over night.

Recently the game was shut down because the creator said "it was too much to handle" after receiving 50k in add revenue a day. He didn't speak out a lot of why he did this but he said that if you already have it downloaded that you are fine. 

Source:IBtimes