Hertz Sense is a rhythm-sense mini-game that measures how accurately you can match a target frequency (Hz) using gentle wrist motion only. ■ How to Play 1. Pick a target from 0.5 / 1.0 / 1.5 Hz (or set a custom value in 0.1 Hz steps) 2. Press START — a 3 → 2 → 1 → GO countdown begins 3. Move your iPhone left and right with gentle WRIST MOTION ONLY for 5 seconds 4. The result screen shows your measured Hz, the delta from target, and a graph comparing your motion vs the target ■ Features - Capped at 1.5 Hz — gentle wrist motion only, no full-arm shaking - Built-in safety auto-stop if excessive motion is detected - Mandatory safety guide on first launch - Two visual themes: Cyber (neon hacker style) and Soft (calm cream) - Bilingual (Japanese / English) with kid-friendly explanation of frequency - Fully offline — no network access required ■ Play Safely - Hold the iPhone firmly with one hand (a wrist strap is recommended) - Use only your WRIST — do not swing your arm - Do not use while walking or running - Play in an open space with no people or objects nearby A fun way to experience the physics concept of "frequency" with your own body — works well as a learning aid for students too.
