What are some alternatives?
When comparing GIPHY Says and Tall Tweets for Google Slides, you can also consider the following products
Guggy - Make your friends laugh with personalized GIFs
Plotaverse - Photo animation made easy, animate like the pros
GifLab - The easiest way to create GIFs on your iOS device
Instagfy - Make a GIF with your most popular photos on Instagram
GIPHY GIF maker - Create animated GIFs from videos (by Giphy)
Gifs - Search through a library of hundreds of GIFs that you can send in your messages or that you can share to social media pages.