Reaction Lab is a compact timing trainer built around fast color matching and streak building. Each round presents moving pulses on one or two lanes. Tap the matching color when a pulse reaches the hit line and keep your streak alive. The timing window changes with difficulty, so you can choose a more forgiving pace or push for tighter reactions. The app keeps everything local. Your best combo, success rate, streak history, and recent round results are stored on the device with no account required. You can review recent rounds, compare accuracy, and clear saved data at any time. Use the settings screen to adjust difficulty, enable automatic round chaining, show lane labels, or switch to a more compact layout on smaller screens. A short loading screen appears on launch before the main experience begins. Reaction Lab is designed for quick sessions, repeated practice, and simple offline play.