My Jumble uses GIF events, not an API. You can upload your own favorite #GIFs with it, or search for some on GifBuddy, and they get published to the relays and persistently cached on your machine. That way, other people can use them and they're available to you offline.

It's only slow, the first time you open it. After that, the cache loads immediately and then it adds more from the relays, if it finds some.

Have fun! 😊