Better layout on small screen

Is your feature request related to a problem? Please describe. In split screen, the layout (buttons position) is not usable and it missing the basic operations (add, times, ...)

Describe the solution you'd like A perfect solution would be to adapt the layout according the size of the app (responsive). Another alternative would be to hide advanced operators in small screens (root, modulo, ...)

Describe alternatives you've considered

Additional context I use a lot the split screen to show, at the same time, a logic game and this calculator.