App Locker – Security Android Application App Locker is a light app protector tool to protect your privacy in mobile apps. The cute lock is designed upon Android system level, to provide fully protection to your privacy. After you set a list of protected apps, there will be lock pattern protection when the protected apps starting. Do you want to increase the security of your apps and stop others from meddling with the apps on your phone? App Locker can help you immediately!