It's great to have lots of options of apps, and today's Daily Mac App adds to the plethora of colorization apps. iSplash is a selective color app just like Colorize and ColorWash, which we've covered before.
iSplash is probably the simplest of the colorization apps we've played with so far. It's got an "open from iPhoto" dialog (although it'll open photos using Finder too), simple "Splash" painting tools (a brush) and undo/redo. There aren't any fancy fill features, or even a simple fill tool for that matter, but you can do just the same manually with a resizable brush tool that's managed with the "Splash size" slider on the tool bar.
You can zoom in for precision work, and when you're finished you can export the image as a PNG. There aren't any options to speak of (you can't change the output format for instance), but iSplash will accept photos from anywhere and in PNG, JPEG, GIF, TIFF and BMP formats.
If you're looking for a load of features and output options, you should look elsewhere. In fact, feature for feature, ColorWash is a better pick, especially since they're both on sale for US$0.99.
It's good to have options, though, and that's just what iSplash is: another option. It'll do the job, just not as well as some others.