Layers is the coolest screenshot app I’ve ever used
Don’t get me wrong, I still use Skitch1 for quick and dirty screenshots and annotations. In fact, I use it more than Layers. But Layers gets my vote for coolest screenshot app of all time.
Everything. On. Your. Screen. Is. A. Photoshop. Layer.
Do I need to say anything else? Try it yourself, they have a free trial.