Hi, I used gtk-recordmydesktop (beware it will freeze your desktop under Ubuntu 17.10 Gnome but works fine under Unity). It gives you an .ogv file and then there's some editing to get a gif. I described the process at the end of: https://blog.openbloc.fr/javascript-es2015-starter-kit/

Mainly convert the .ogv to .mp4 with ffmpeg (don't have the command here), create a png palette from the video so your gif colors are more accurate and use ffmpeg to create the gif:

    ffmpeg -y -i video.mp4 -vf fps=10,scale=800:-1:flags=lanczos,palettegen palette.png
    ffmpeg -i video.mp4 -i palette.png -filter_complex 'fps=1,scale=800:-1:flags=lanczos,setpts=0.25*PTS[x];[x][1:v]paletteuse' todoApp.gif

This gives you a 800px wide gif, with 1FPS, and sped up 4 times (setpts=0.25) :)

Why make a gif from this rather than a webm (seeing as you obviously know what you're doing with ffmpeg)?

The ghost blog allow me to directly upload images to my cdn, it's a little more work to publish a video and I was too tired when finishing this article yesterday to think of better options anyway :)

What does webm support look like these days? Last I checked neither Safari nor IE had webm support.