Last updated: June 10, 2026
The short version: Reaction Light Trainer has no accounts and does not track you across apps. Your training data stays on your device. The free version shows ads through Google AdMob; a one-time “Remove Ads” purchase turns them off. We run no analytics SDK of our own, and multi-device sessions stay on your local Wi-Fi — nothing is sent to our servers. The only information we ever receive directly is what you type if you choose to contact us.
Your training history (sessions, reaction times, scores) and app settings are stored locally on your device only. They are never uploaded. Deleting the app deletes this data.
In multi-device mode, your phones and watches discover and connect to each other directly over your local Wi-Fi network (using Bonjour and a peer-to-peer connection). Session data — which light is lit, taps, scores — travels only between your own devices on your own network. It does not pass through, and is not stored on, any external server.
The free version displays ads via Google AdMob. To show ads and measure them, AdMob may process device and usage information such as a device identifier, coarse/approximate data, and diagnostics, as described in Google's policies. We do not show the App Tracking Transparency prompt and do not track you across other companies' apps or websites; ads are contextual and use Apple's SKAdNetwork for privacy-preserving attribution. See Google's advertising policy. A one-time Remove Ads in-app purchase disables ads entirely.
“Remove Ads” is processed by Apple; we never see your payment details. The ad-free entitlement is stored locally on your device.
If you use the optional “Contact Us” form, we receive the email address, subject and message you submit, and we use them solely to respond to you. We do not add you to any mailing list or share this information with anyone.
The app is suitable for all ages. Because we collect no personal data, no special handling of children's data occurs.
If this policy changes, we will update this page and the date above.
Questions? Email zachsong@gmail.com or use the contact page.