I am currently using Lemmy.zip through the app voyager.
I can also see content from other places like hexbear and fedinsfw.
If I login to lemmy.zip on a desktop I can use my voyager credentials. But I am only able to view lemmy.world and nothing else here.
If I login to fedinsfw on desktop I can seemingly access a multitude of places such as I can on voyager, including lemmy.zip.
I’m sorry if this is such a dumb thing to get confused about. I’ve heard explanation for what all this is, but I’m still just not quite sure I understand.
Some servers have other servers blocked so you wouldn’t be able to see content from there, others might not be running the newest version of the lemmy software, or are using something else altogether. Lemmy.zip is pretty good about updating and not blocking other servers which is why I like it.