GrapheneOS It can't directly transfer to another device yet, but it's planned as a core feature for our replacement backup app that's on the backburner right now.
A good reliable backup of all apps and their data seems like a core feature of any OS, and yet, it remains "on the backburner" in spite of the many posts on this forum on how unreliable current option (seedvault) is. Just saying (...and hoping the project would re-prioritize the need for a proper/fail-proof backup solution).