@witchescauldron hm, you should try dat-ecosystem projects, especially keet.
it works on mobile and it doesnt require servers or backends, it uses the p2p networo to punch their way out of most network situatiins to establish direct p2p connections and it also uses the p2p network to blind relay in situations where the network is so locked down that holepunching get too hard, but thats a rare scenario anyway.
dat is basicallly torrents with version control integrated for any type of data