If you're craving some Photoshop functionality but don't have the necessary funds, you might be looking for an alternative. Photobie is one option, a free graphics editor that has a major advantage over similar free competitors - it supports layers.
This is undoubtedly Photobie's main selling point - support for layers is one of the keys to advanced graphics editing. It's not all that matters however, so Photobie also has all the other graphics tools you would expect, including cropping, resizing, effects and filters, some of which you'd expect to find in a paid program. The app also supports various screen capture modes and has a GIF animation tool.