A doodle epidemic is spreading through smartphones across the land. Doodle games are popping up everywhere you look--on iOS and Android devices alike. There might even be one in your pocket right now.

What distinguishes doodle games from the pack is their graphics, which look like something you might scribble in the margins of a piece of paper. In fact, the backgrounds of most doodle games are lined to look like notebook or graph paper, and they generally have a whimsical sense of humor. Doodle Jump was one of the first games to employ this aesthetic, and it's also one of the best.