I run a small gaming zone and need a straightforward Android app that lets me: • Tap “Start” when a customer begins playing and “End” when they finish. • Automatically calculate the total duration as soon as the end time is entered. • Display the charge right away (I’ll supply my fixed rate per minute or hour in the settings). • Let me record how they paid—cash, UPI, card, or wallet—and the exact amount collected. A clean, single-screen flow is ideal; local storage (SQLite or Room) is perfectly fine. No fancy analytics or sign-up screens—just a quick way to log play sessions and payments so I can review them later in a simple list or daily summary. Source code plus an installable APK is all I need.