I also use Resilio Sync because it is one of the rare solutions here that provide an iOS client. The app is quite poor compared to the Dropbox app, you can just

I also use Resilio Sync because it is one of the rare solutions here that provide an iOS client. The app is quite poor compared to the Dropbox app, you can just about use it to open, sync files both ways but that’s it. Also, you cannot share individual files or folders with others.