Angry Birds
angry birds start screen

Careful! Tapping the "Play" button for "Angry Birds" is basically like saying, "Yes, I'd like to experience missing time."

©iStockphoto.com/Sean Locke

If you own an iPad or an iPhone -- or any kind of smartphone or tablet -- you've probably already played "Angry Birds." The most ubiquitous mobile game on the planet had been downloaded more than 200 million times as of May 2011 [source: TechCrunch]. "Angry Birds" hits all the basic points of an addictive mobile game.

It makes simple use of the touchscreen: Players fling birds from a slingshot like projectiles, trying to cause as much destruction as possible before advancing along to the next level. The game's rudimentary physics and the different types of birds add just enough variety to keep the formula interesting. There are 120 levels, making "Angry Birds" a fantastic value proposition. "Angry Birds" addicts can download "Angry Birds Seasons" and "Angry Birds Rio" for even more levels.

As of August 2011, "Angry Birds HD" is free for the iPad in the iTunes App Store. "Angry Birds Rio HD" sells for $2.99 and "Angry Birds Seasons HD" sells for $1.99.