Application Lock - Media Vault is a free Android app developed by Divyesh Devlani that provides users with a simple and quick way to lock their applications and prevent unauthorized access. The app offers a variety of locking options including PIN, pattern, and fingerprint recognition. It also offers an Image Vault, Video Vault, and File Vault to move sensitive data from the device memory to the vaults.

One of the unique features of Application Lock - Media Vault is its random keyboard and invisible pattern lock, which makes it much safer to lock apps. Additionally, the app provides an uninstallation prevention feature that prevents unauthorized users from uninstalling Application Lock. The app also has a Privacy Lock feature that prevents others from seeing your album, video, files, and other sensitive applications.