I created rugmi.eu as a response to the lack of decent gif reverser sites. I wanted something where I could just take any gif on imgur, change the url slightly, and BAM, it's reversed. That's the idea of rugmi.eu.
How does it work? Simple. Take any imgur URL, such as http://i.imgur.com/UApL2xt.gif, and put "rewind" in front of "imgur.com" in the URL bar. Congratulations, your gif is now reversed. No uploading, no sign-ins, none of that.
The first time a reversed gif is loaded, it may take a while to appear. Patience padawan. However, after that the gif will be cached on my server, so that loading times will be speedier later. Gifs are stored for 1 month after last access, meaning if it goes un-looked-at for 30 days, it'll need to be re-reversed.
Give it a try:
For an even easier way to use rugmi, drag this rugmi: gif reverser bookmarklet to your bookmarks bar.