Privacy Policy
Last updated: June 23, 2026
App and developer
This Privacy Policy applies to 鞭甩发力器 / Whip Power Trainer (Android package name com.zach.bianshuai) ("the app"). The app is developed and published by Zhenyu Song, an independent developer operating 100for1.com ("we", "us", or "our").
Whip Power Trainer is a badminton whip-snap training tool. Training calculations are performed on your device. This policy explains how the app handles information when you use its optional online and advertising features.
Information we collect
The app has no account or login. Most training data stays on your device. Information is sent off-device only when you use the optional leaderboard, or when advertising is loaded as described below.
Device sensors
To simulate the training stick and rate your swings, the app reads your device's motion sensors (accelerometer and gyroscope) while a training session is running. These readings are processed in real time on your device and are never uploaded or stored off-device.
Data stored on your device
Your weight settings, language and voice preferences, and the current session's swing history are saved locally on your device only. This data is removed when you delete the app. It is never sent anywhere.
Optional leaderboard
If you choose to submit a score to the leaderboard, we send and store the name, profile photo, city and country that you provide, your submitted score and equipment settings, and a randomly generated app-specific identifier. Your name, photo, city, country, and score are displayed publicly on the leaderboard. The identifier is used to associate your submitted records and support moderation; it is not your hardware advertising ID.
The app may request location permission only to suggest your city and country for this optional feature. Your precise coordinates are used on your device for that lookup and are not sent to our leaderboard server. You can deny permission or enter a city manually.
Microphone and camera
The app does not use the microphone or camera. Voice feedback uses your device's built-in text-to-speech to speak a rating; nothing is recorded.
Third parties and tracking
The free version uses Google AdMob to show app-open and interstitial ads. Google may collect or receive device and online identifiers, IP address, app interaction information, and related diagnostic information to deliver, measure, and prevent fraud in advertising. Where required, the app presents Google's consent flow; personalized advertising is subject to your consent and device settings. Google's handling of this information is governed by the Google Privacy Policy. We do not sell your personal information.
Children
The app is suitable for all ages and collects no personal information from anyone, including children.
Changes
If this policy changes, the updated version will be posted on this page with a new date.
Contact
Questions? Email zachsong@gmail.com.