Playing Capture Go is an excellent way for beginners to learn about the tactical fundamentals of Go - the first player to capture a stone wins! It can be one of the first steps after learning the rules of Go, using some simplified rules shown here . It's really quick to finish a game.
There is a new app for the iPad (and iPhone soon) at a cost of £1.49 called GoforKids which is purely for Capture Go (3 levels). If you can't find it in the App Store, you can find it via http://go-for-kids.appspot.com  which also includes instructions! It's probably a good idea to read the instructions before using it anyway!
The app below is written in Java, so will not run on some platforms, such as the iPad/iPhone, and on others where Java is restricted, so (sadly) this may not work for you:
You can customize the board size, the type and strength of the computer opponent. You can even use this applet to play Capture Go with another human player.
There are two types of computer player:
The Settings dialog pops up only for the Alpha-Beta computer player.
The Capture Go applet was written by Sorin Gherman