I purchased Doodle Jump in June 2012 for the iPod. I heard a lot of good things about the game and I have tried this game in 2010 on a pupil's iPhone. The basic rule of Doodle Jump is to jump as high as you can while avoiding obstacles and enemies. There are power-ups and upgrades which can be used in-game like the Shield, the Jetpack and a cannon which sends you back to the arena if you fall off.
There are also different themes in the game which are Christmas, Easter, Halloween, Ninja, Football and some others. My favorite one is the Ninja theme because of the detail that was put into that theme. With certain themes, there are shops for you to buy upgrades and power-ups to help you. How do you buy them, you ask? Collect things like Easter Eggs (Easter) or Candy (Halloween) to buy these items. The problem with this is that they do not come cheap, which means you will have to either play the game a lot or use the in-app purchase system to buy more of those items :( This game also has online multiplayer in which you can race to see who jumps the highest without falling.
I thin this is a fantastic game for the smartphones and tablets, despite the problem with the buying of upgrades. I recommend this game to anyone looking for some spare time to kill.