SlidesPro - Google Slides add-on w/ shortcuts, YT videos & more
Giffing Tool - Giffing Tool is simply put: The fastest creator of high quality captioned GIFs available.
Slideflow - Turn your Google Slides into a website in seconds.
GIPHY Create - Create animated GIFs from videos (by Giphy)
Brand Kit by Premast - Manage, share and create branded content in PowerPoint
Instagiffer - Create GIFs from anything!