Rather than copy&paste from other parts of the site, here is An intro to Mobian and What is Mobian?

If you are interested in seeing some videos about Mobian, there are some reasonably up to date videos here.

The project is driven by a community of volunteer developers and users; it is not a registered organization. The project has been founded by @a-wai.

This wiki is intended to collect instructions, tips and tricks for users of Mobian, and is editable by ordinary users. Information for developers can be found on our Salsa.Debian git repositories (although there is quite a bit on the technical workings of the PinePhone here as well…). You will find another Mobian wiki at https://wiki.debian.org/Mobian; as of 2023-08-07, there is an unclosed Wiki Transition Debate about shifting to wiki.debian and freezing wiki.mobian-project.

You might want to look at the installation instructions, the Frequently Asked Questions, or the tweaks pages. If you want to see which apps are suitable for mobile phones, check out the apps section.

(Adapted from here)

As with every Matrix room and IRC channel, we encourage you to stay around for a while after you ask a question, and listen to the various discussions. Some people usually read everything that happens there, so it is likely that someone will answer you if they have the answer (Not getting a response usually means no one knows the answer, or the person who knows the answer has not read it yet).

Due to this, please make extensive use of the off-topic channel to lower the noise in the others, and make the lives of those who read the entire backlog easier. Also note that everyone doesn't read every channel; if you want to draw someone's attention, type their name to ping them (doing this too often is considered rude, though). To prevent flooding the channel, please also use a service like https://bpaste.net/ instead of pasting your logs directly.

Remember that when you close your IRC client to go sleep, you miss out on half the planet. Please consider using Matrix for offline history and better rich-media support.

Special note for Matrix users: you can set the notifications setting to “Mentions only” so that you will only disturbed when someone writes your name.

(Adapted from here)

Some channels may not allow you to speak unless you register your nick.

• Open a new chat with “NickServ” (Matrix: open a new chat with @_oftc_NickServ:matrix.org)
• Register your account by sending this to NickServ: register <password> <email> (example: register dhg235h234jbb you@hello.world)
• Verify your account at services.oftc.net
• Write checkverify to NickServ
• Login by sending this to NickServ: identify <password> <nickname>

You can probably configure your chat client to identify you automatically. Instructions for automatic login with Matrix are here.