I use syncthing. It's awesome for computers. Coming from Dropbox, then Nextcloud, I find it solves all my needs much, much better, at least on well-supported platforms.
I love how I can decide what to sync where, and even create my own topology of sync-devices if I like. That may sound like crazy complex stuff and over-engineering and what not, but it was a solution I landed on organically, just through normal use.
That said, it's not entirely smooth on iOS and you sometimes needs to manually launch the (third party) app to force a sync after changing some files.
I love how I can decide what to sync where, and even create my own topology of sync-devices if I like. That may sound like crazy complex stuff and over-engineering and what not, but it was a solution I landed on organically, just through normal use.
That said, it's not entirely smooth on iOS and you sometimes needs to manually launch the (third party) app to force a sync after changing some files.