Citrine on android literally took me 10 min to set up. There is also a simple privet server (no code gargin) with umbrel unfortunately you have to pay $500 for hardwar though umbrel is like a new ios device from what I could tell. You could set up a HAVEN relay (documentaion on how) But if your looking to back uo your notes and broadcast simply go to

NostrSync

Fetch, backup and broadcast your Nostr events

put in your npub (public key) the site will then back up all your infor to a .Json file and also broadcast to other relays automatically