Retroshare allows you to establish encrypted connections between you and your friends to create a network of computers, and provides various distributed services on top of it: forums, channels, chat, mail... Retroshare is fully decentralized, and designed to provide maximum security and anonymity to its users beyond direct friends. Retroshare is entirely free and open-source software. It is available on Android, Linux, MacOS and Windows. There are no hidden costs, no ads and no terms of service.
Get the software @ https://retroshare.cc/
The RetroShare ID to connect with is:
ABBoJ5fsnoFayyBIJYYlRaXLAxQ3CbybJPUM1BTbdmcS+IjL8xLcXwEFZ2VrdXSQRAAAAAImlmh5Z3psemwyaHh6bnhmeGd6bDNzZ2hvdm51YjVwamY1NTVvcDcyZXZxYWdpaHN6a2h0bnoyYmFkLm9uaW9uBAMK/p4=
Make sure to select "Hidden node (over tor)" when creating your node. See screenshot, otherwise your incoming connections may not work.
The dev was definitely ahead of their time with RS. The platform is pretty fun and engaging, as well as truly decentralized.