Only reading text changes; buttons and the frame keep their sizes. Interface size scales everything. Both are kept in this browser.
Sound
Home Screen
To add this to your phone’s home screen so it loads as a web app (without the address bar and bottom buttons):
iPhone / iPad (Safari): Share button on the bottom of the screen › Add to Home Screen. Make sure to select “Open as Web App” to ensure it displays properly.
Android (Chrome): menu (⋮) › Add to Home screen or Install app.