Sync through iCloud or through the app manufacturers servers. Most apps I use are real apps that live on my local device. Then some of them sync through iCloud if I want to use sync. This is something I as the user can enable or disable in the app, and it costs me no subscription fee.

I think that this is much superior to using fake apps that live on some web server. It comes with great drawbacks even when it is on the web server of the app manufacturer. Ten times more pain if I have to host it myself.