when viewed in-browser on a small screen, the reg page does not auto-scale, and the submit button appears offscreen. The text box also doesn't respond to pressing Enter, and on mobile it doesn't have a submission button on the virtual keyboard (related?). If the keyboard obscures the button, then you have to press Back to dismiss the keyboard before you can submit what you've entered, which makes for confusing, or at least annoying, UI.
when viewed in-browser on a small screen, the reg page does not auto-scale, and the submit button appears offscreen. The text box also doesn't respond to pressing Enter, and on mobile it doesn't have a submission button on the virtual keyboard (related?). If the keyboard obscures the button, then you have to press Back to dismiss the keyboard before you can submit what you've entered, which makes for confusing, or at least annoying, UI.