The wonderful Fr Eddie Green uses them extensively in his Worshpr toolkit.
Creating them from scratch (as opposed to just simply downloading them) used to be complex, but now I have worked out how to put two simple steps together to make this magic happen.
How to create Animated GIFs from something on a Web Page
2 This enables you to grab all of a web page, or just a tiny part or… record the screen as a video
4. When you have recorded what you want in Nimbus, you can save it. The video format is the rather useless .webm format which even Adobe Media Convertor cannot read, so this is where the next site comes in…
6 For an embedded GIF (I still despite knowing different still call them Gg-if with the hard G rather than the soft J-if, sorry it’s too embedded) in a tweet, I reduce the size to 320×240 for square (4:3) images or 320×180 for widescreen images
7 In a few moments, the GIF will be downloaded. Note you can do all kinds of conversions as well, so you can convert anything into anything. This is good if you want the .webm in .mp4 format so you can put it in another video.
These are some quick examples: