Security Lock (SL) is the best mobile solution against theft and unwanted access to your phone. This quality app offers unbeatable value for money, giving you the power to protect the important information and personal data on your phone even remotely. Five reasons Security Lock is a must-have app: With SL you can stop curious friends or intruders from spying on your phone. Lock your phone with a password code. You can expose a thief by activating a loud alarm. Set the remote-activation alarm.