Just a side note but both Simplex Chat and Briar are free of unique identifiable IDs.
For Simplex Chat it uses hash tables. It still has a centralized server (which you can self host) but you can use the built in Tor functionality to hide your IP.
For Briar it is totally decentralized. All messages go directly over Tor but it also can use WiFi and Bluetooth. It supports group content types such as Forms and blogs. The downside is that you need a connected device. You can also use Briar Mailboxes on a old phone to receive messages more reliably.
Just a side note but both Simplex Chat and Briar are free of unique identifiable IDs.
For Simplex Chat it uses hash tables. It still has a centralized server (which you can self host) but you can use the built in Tor functionality to hide your IP.
For Briar it is totally decentralized. All messages go directly over Tor but it also can use WiFi and Bluetooth. It supports group content types such as Forms and blogs. The downside is that you need a connected device. You can also use Briar Mailboxes on a old phone to receive messages more reliably.