Anti-Theft Security Alarm is a free Android app developed by SISA Ltd. It is a simple and handy security app that protects your phone from theft and keeps it safe in public and work places. The app allows you to set a PIN that only you know and you can choose from six different alert sense modes to trigger the alarm. The thief cannot stop the alarm without knowing your PIN, and you can even use your fingerprint to switch off the alarm. The app also triggers a loud alarm even if your phone is in silent mode and vibrates and flashes the flashlight when the alarm is triggered.

With Anti-Theft Security Alarm, you can choose any alarm sound or even set custom alarm sounds of your choice. You can also customize other settings, such as the alarm volume level and what happens when someone tries to power off or restart your phone. The app also allows you to display the ringing screen over the mobile lock screen and clear app caches within the app itself. Please note that the app requires storage and location permissions, and it may not work properly if you use any task killer app or have battery saver/restrictions enabled.