Sly - Friendly Image Editor

A friendly image editor that requires no internet connection or preexisting expertise. Just some photos and have at it.
The app allows you to adjust attributes like brightness or contrast as well as add effects like a vignette or a border. It also allows you to flip, rotate and crop the image to your heart's desire. If you're a pro, you can even preview your edits on a histogram.
When you're done, just save the photo with the quality settings of your choosing. You also get a choice in whether or not to keep metadata such as location information.