Drench is PC version of a flash game of the same way. It's a puzzle game that's wonderfully simple to grasp, but difficult to explain!
The game starts with a big grid of colored blocks. Beginning in the top left, you have to 'drench' the entire grid with one color. You do this by changing the color of the block. When you change a block into the same color as a neighboring block, you expand the drenched area, and by repeated color changes, the area will increase. There's a limit of thirty moves per level, so it's game over if you don't drench the board in that many moves.
This is a surprisingly addictive game, although the concept isn't original. Finding the most efficient way of drenching the screen is really compelling, and completing a level is pretty satisfying. There are a couple of criticisms though. Firstly, there are no options for difficulty, and it does get hard very quickly, and secondly, if you lose a level the restart button is broken and you have to restart the game.
Despite that bug, the game is enjoyable and will certainly keep you entertained for a while. Hopefully it will be fleshed out in future versions.