roshang1t/TimeKeeper ? reverse-engineered prompt

Build me a simple Timekeeper app for Android that lets people track time in two ways, a count up timer and a countdown timer.

I want it to feel clean and easy to use, like something I can open quickly during everyday life. The main screen should let me start, pause, reset, and switch between count up and countdown. For countdown, let me set a target time before starting, and show a clear alert when it reaches zero. For count up, just keep tracking elapsed time clearly and accurately.

Make it look good on a phone, with a modern dark and light friendly interface, smooth updates, and a layout that is easy to read at a glance. If it makes sense, add small quality of life touches like saving the current timer state, basic history, or quick presets. Use the existing React Native Expo setup in the project, and look up current docs online if you need to.