The automatic lock-screen technique makes Android Smartcover.

The ipad's dedicated protector, "Smart vinyl", is certainly familiar, using the principle of magnetic induction to combine open protectors with screen introductions, and many developers use its features to develop interesting apps. But now there are a lot of Android devices do not have magnetic induction, you can not enjoy the convenience of it, but today small set to recommend an app, use it can be arbitrary protective sleeve into a "Smart vinyl." The app is named "Smart Vinyl", which uses a cell phone's proximity sensor to automatically turn off the phone screen when the cover is protected. When you open the app, click on the Intermediate button and click "Activate". When the button in the main interface turns green it means it's activated, and then we can block the distance sensor on the phone, and we can see that the phone is automatically locked. If you feel too responsive, you can also adjust the response time in app.