The Flash of bombs going off
Grid Riddle is a series of extremely simplistic jigsaw puzzles with maddeningly shrinking time limits. Bomb Factory is a game in which you rotate arrows to direct bombs into conveyors of the same color. Shoot 'em Up is a basic can-shooting game in which you shoot at bombs (by tapping them) to keep them up in the air. All of the games are pretty simple, but diverting; Bomb Factory in particular can get hectic, after fooling you with a slow start.
Also they're free.