The Quick Capture camera feature of Moto X smartphone lets you take photos with a twist of your wrist, even when your phone is asleep – a quite useful feature for capturing something quickly. You only need to twist your wrist twice to launch the camera anytime. Now you can bring the same function to any Android phone with an app called QuickCamera.
QuickCamera, which is a free app developed by Suyash Srijan, is designed to bring the Moto X’s Quick Capture feature to other Android smartphones. With this app, you can launch your default camera app just by rotating your phone twice. Within seconds (2 – 3 seconds, based on your phone rotation and sensor response) your camera will be activated.
QuickCamera is a gesture-based app and just like in Moto X, your phone will vibrate when you rotate it indicating that your gesture is recognized and the camera app is going to be opened. It is to let you know that the gesture is recognized and there is no need to rotate more, or it could give some errors.
The app will run both in sleep mode and in on mode. For now, it uses the accelerometer to detect your movements and turning the camera on, but in the future development, it should be the gyroscope for better accuracy. Also, it uses the proximity sensor of your device to detect whether the phone is in your pocket or not to avoid any errors.
Please note that the app is in developing stage and it is not available publically in Play Store. To try this app you need to be a part of the beta group. Just go here and sign up with your Google account to become a beta tester. (source)