See the Pen Holiday Feature Folding Cards [Pure CSS] by Madalena Aza (@Madalena-Design) on CodePen.

Befunky is simple, intuitive, and one of the best options for performance on this list. It features a variety of awesome elements to boost your image quality as well as a nice and simple collage feature. Like Fotor above, Befunky also contains many design elements that allow you to create lovely postcards, brochures, posters, slides for Powerpoint presentations, and invitations with only a few simple steps.

If your goal is social networking posts, printable assets, or a presentation for a client, then Befunky is a good option for you. While it may lack features as wide-ranging as other options on this list you would be hard pressed to find a faster and more efficient option for cranking out simple creatives in a reasonable time frame.