The Thunder app is still my number one candidate.

I guess thats what the Kickstarter is for. Also, don’t forget that the benefit of sup might be communication across all fediverse platforms, which means that as long as you have a single account in the fediverse, you can talk to all other accounts. Quite a bigger network than Signal, which is only a single platform.

Pixelfed user numbers seem to rise a lot: https://discuss.tchncs.de/post/28627765

https://vernissage.photos/home may be better than Pixelfed. https://discuss.tchncs.de/post/28641458

Also, introduce them to the gup.pe concept where social groups can be formed on Mastodon:

https://a.gup.pe/