Jami and Bridgefy are two cross-platform (inc iOS) Peer-to-Peer messaging clients that bypass censorship
Whilst Briar is an excellent P2P messaging client (requiring no Internet) it still does not yet run on iOS. So to be able to connect to everyone, you want to consider clients which do connect as widely as possible. As with all P2P clients, your friends all need to also have the same app installed....
