It allows to do stop motion animations: http://gif.gg/0HV7by http://gif.gg/tp7j5Sq
Here's the bluescreen GIF-maker I made with it: http://mapmeld.github.io/bluescreen-gif/
This is a neat project by the way. Thank you for your work.
640x480 produces huge gifs (20+MB for 10s) since dithering is not yet implemented. You can use any online gif optimiser, though.