The lack of style was intentional, it took me less than the better part of an hour to build this. I built it because I needed to convert a GIF to a sprite and didn't want to have to use Photoshop. I am planning on a bundled JavaScript library with weekend actually so you'll be able to pause, play and rewind the sprites as if they were videos. I have some code for another project that does this, but it's not in a form of easy to use drop in code. And the reduced file size is because I am compressing the JPG images when the GIF is split, then once the frames are combined, I am compressing further. At first I thought this would result in poor quality sprites and not make a difference, but it seems the double compression works really well.

Thanks for the nice words, I hope someone finds it useful. If people find it of use, I might devote more time to making it a little nicer and more feature-packed besides the JavaScript library I'll be making for it this weekend.