Android Calculator App Development

I need a straightforward utility-style Android application that serves as a responsive calculator. You may build it in JavaScript (React Native, Ionic, etc.) or Python (Kivy, BeeWare, Chaquopy—whatever you are most productive with).

Core requirement
• A clean calculator interface that handles reliable, real-time calculations. At minimum I need the standard arithmetic operations; if you can architect it so scientific or financial functions can be added later that would be even better.

Deliverables
• APK ready for installation on current Android versions
• Complete, well-commented source code
• Brief read-me explaining framework setup, build steps, and how to extend the operation set

Acceptance
I will install the APK on a physical device and cross-check results against known calculation outputs. All buttons should be responsive, the display must resize gracefully on common screen sizes, and the app must launch without errors on Android 8+.

Let me know which tech stack you prefer—JavaScript or Python—and an estimated turnaround.