Free image editor based on the Windows version
Photoscape X for Mac is a free photo editor that's been on Windows for years and has finally arrived on Mac. Although it doesn't quite match-up to the Windows version, it includes tons of filters, tools and special effects that are hard to beat in a free photo editing tool. It's nowhere near the level of Photoshop, but it's an easy to use alternative and it makes photo editing a lot more fun.
Packed with filters and effects
Photoscape X for Mac includes just about everything you need to view, optimize, edit, print and have fun with your photos. In particular, there are several filters and effects to apply to your photos. The Mac version does lack certain tools that are in the Windows version however. The Batch Editor, Page (with which you can create collages according to preset layouts) and the Combine tool are all missing on Mac for example.
Well designed slick OS X user interface
One of the first striking elements in Photoscape X for Mac is its uncluttered interface design. Everything is laid out in a logical and easy to access manner. From the Photoscape X for Mac main window you can choose what you want to do: view pictures, optimize those that didn't come out so well, print several photos on a single page collage-style or perhaps add any of the dozens of filters and special effects included in the program.
Not quite up to the Windows version
Photoscape for Mac features lots of cool ways to add effects and filters to your photos but until it matches up to the Windows version, it can't really be considered a serious easier to use alternative to Photoshop.