I'm an old redditor that left the platform for Lemmy. I have been using Sync and using lemm.ee. I have heard so much about activity pub and simply don't understand how to use it. Do you use a browser to visit another website that is like a Lemmy instance? Is there an Android app that connects a bunch of instances like pixelated and Lemmy instances together? Or is Sync able to do all this but there is a setting I need to do. Can someone please help shed some light to this? Thank you.