FotoJet is yet another online photo editor. Like many others it provides a simplified user interface for manipulating images. Two things in particular that I liked about this service are collages and social media banners.
Collage editing makes it really simple to combine multiple images into one (see the screenshot above). Social media banners greatly simplifies the creation of images that can be used for Facebook, Twitter, Tumblr, and YouTube channel headers. No more searching for the appropriate dimensions, image sizes, and the like!