OVERVIEW
For this challenge you are asked to build a very, very simplistic ‘calculator’ app interface on either iOS or Android. Your app should present a simple layout. Your app need not do anything when the buttons are pressed, but it must be able to rescale itself automatically to any reasonable display size. (That is, generally speaking, any phone supported by your IDE. Looking not-ridiculous on a tablet is not required.)
LAYING OUT THE CALCULATOR
Your calculator must look more or less like a calculator. At the minimum, it must include a full (decimal) number pad, along with buttons for the basic operations (+, -, *, /), equals, and clear. You may include other buttons if you wish.
Your interface must take up either the full screen, or a deliberately sized subset of the screen. For example, you could choose to fill the entire screen (like the Android example, above), or a particularly shaped section (the iOS example puts everything in a 2:3 box), but you may not simply build an interface that fits the smallest device and not have it rescale. The buttons must form a neatly aligned grid. Buttons which are out of alignment with one another will not receive full credit, even if they rescale successfully.
RESIZING THE LAYOUT
Your layout must automatically adapt to being displayed on devices of various sizes. It is likely possible to handle this programmatically, but I would recommend using the constraint system available on your chosen platform (or, again, SwiftUI). I will test your interface by loading it in Xcode or Android Studio, as appropriate, and then changing which device is used to display the interface. In cases where it’s not clear that the interface is being scaled (or with SwiftUI), I’ll run your app on simulated devices. Your interface must remain fully visible and appropriately scaled regardless of the (phone-class) device I choose. You do not need to account for rotating the device, though you may if you wish.