Twist Camera is an ad-free, open-source Android app that listens for a Motorola-style double wrist twist and requests the system camera.
This is a Fold-focused feasibility prototype. Android 17 requires the user to grant "display over other apps" access before a gesture can reliably launch the camera while Twist Camera is not visible. The app never draws an overlay; the grant is used only for Android's documented background-activity launch exception.
The Galaxy Z Fold8 exposes its gyroscope as a non-wake-up sensor. Real-device testing confirmed reliable launches while the display is awake, but not while the phone is fully dozing with the display off. The ongoing notification remains a one-tap camera fallback.
Gesture length can be set to 2, 3, or 4 alternating twists. Detection sensitivity can be set to Easy, Balanced, or Deliberate. The tested default is 2 twists with Balanced sensitivity.
All motion processing happens on-device. The app has no network permission and contains no ads, analytics, tracking, accounts, or proprietary SDKs. It does not request camera, microphone, storage, or location access.
- Install Android Studio with Android SDK 37 and JDK 21.
- Open this directory and allow Gradle to sync.
- Run
gradlew.bat test assembleDebug.
Apache License 2.0. See LICENSE.