PixelDroid for Android. It’s available on F-Droid too

Well that aged like fine wine (talking about Embrace Extended Extinguish and how Google abandoned XMPP):

In theory, a company like Meta could run that playbook here. It could launch Fedigram or Fedbook or whatever, gain a lot of users, and then slowly shut out the broader ecosystem.

The Youtuber TheLinuxExperiment did a Quick start guide to the fediverse video 6months ago, focusing on Mastodon Peertube and Pixelfed. I think Lemmy was only briefly mentioned though

While not a video, there are a few posts with concrete examples:

Brief infographic

Lemmy.world starting guide

Guide to help new lemmy users find and subscribe-to (remote) lemmy communities

Subscribe to Kbin threads from Lemmy