ColorSplash is a simple, fun and cool iPhone app that allows you to make certain parts of a photo grayscale and other parts colored.
Although this is the only function of this app, it still is a great app because of its ease of use and great results.
I ColorSplashed this photo below in around 10 minutes (wow I look so handsome in it).
Tip: Zoom in for easier viewing and turn on the red colour brush for better control over what you are colouring.
Now enjoy wiping your finger on your iPhone screen!