Peters solution will only work for screen size or/and if zoomed in/out..
You will have to extend the above solution with the help of this extension App Inventor Extensions: Settings | Pura Vida Apps and it’s FontScale block
something like this
Peters solution will only work for screen size or/and if zoomed in/out..
You will have to extend the above solution with the help of this extension App Inventor Extensions: Settings | Pura Vida Apps and it’s FontScale block
something like this