Chrome/Firefox: Ever hate how when you first open a GIF, it loads super slowly with choppy animation? It kind of ruins the GIF experience. But GIF Delayer is an easy fix that stops the animation from playing till the image is completely loaded.
The extension, available for Chrome and Firefox, does exactly what it says: your GIF animations will be delayed so that they play properly the first time you see them. I tried it out with several GIFs, including a page full of them, and it works perfectly. On Chrome, you can even pair it up with Paused to pause your GIF animations.