Yes, that is one of the reasons why I made HTopia browser-based.
I haven't tried this on iOS, but in Android, if you go to our official website https://htopia.online you get asked if you want to install the app as shortcut in your phone, and when you run it like that, it runs on fullscreen, like if it was a native app.
You can give it a try on iOS and see if it has a similar behavior.