Holy crap that's just `pkg install borgbackup`. I had no idea (my phone is already rooted anyhow, so this will also be able to get data folders). This changes everything. There is also `pkg install restic` btw. Based on the problems with append-only in borg and the lack of those in restic's implementation (I did a short audit on that part of the `restic/rest-server` code, looks solid but don't take my word for it), I might go with the latter but this is a great tip regardless.