Screen Lock is an Android app developed by SUPERYAO that provides a simple and efficient way of locking the screen of your device. This app is completely free and does not have any ads. It is extremely lightweight and won't consume much of your device's resources.

The app uses Accessibility Service to lock the screen and is open-source, which means that the source code is available for anyone to access and modify. This app is perfect for those who want a simple and secure way to lock their device without any unnecessary features or ads. Overall, Screen Lock is a great option for anyone looking for a lightweight and straightforward screen lock app.