This isn't that new of a resource, but one .gif website worth mentioning in the world of .gif files on the Internet is Reverse GIF, which allows you upload individual .gif files, then it essentially gives you a new version of the .gif, only re-arranging its individual frames in a reverse order. It also adds a small watermark to the lower right frames of the .gif file.
If you have some animated .gif files that you want to see backwards, then Reverse GIF seems to be a good tool.
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