Looks good. Nice work! I've not done more than 'kick the tyres' at the moment, but once thing I would suggest is to try and optimize the layout a bit better on

Looks good. Nice work! I've not done more than 'kick the tyres' at the moment, but once thing I would suggest is to try and optimize the layout a bit better on mobile. On a tablet screen in horizontal mode, there's a lot of wasted space round the code entry and the output boxes and you have to scroll up and down from one to the other, as they don't both fit on screen at once. How it works on mobile should be a priority, as something like this would be the kind of thing that, more often than not, you'd idly tinker with, while on a phone or tablet