I tried and tested Syncthing on iOS and Android. On Android there are plethora of options really in terms of syncing, but still I tried Syncthing since I wanted to be ready for Obsidian App which is stated as “coming soon” and read somewhere that will be free to use if we can have our own syncing methods.
As for iOS, there is no official or free app that can do the syncing, but there is an app called Möbius Sync that works. Only catch is, its not free. Rest it works fine. The free version offers just 20MB sync which is okay for daily note capturing and sharing, but for complete vault sync, we need to shell out some money (I can’t right now – student and not sure about using it). I used it with Taio which is mentioned here quite a few times, and it works decently but no ‘wikilinks’ support. Basically, any editor can be used once the files are in the Files App, I guess.
Just wanted to share what I had tried at my level. I hope it helps somebody somewhere 