If you want to protect apps installed on your Symbian phone from friends using it, you can try out Lite – 5CLocker. It is a free tool for Nokia phones which allows users to protect the installed apps on your phone. Also lock apps like Camera,Clock,Calculator,Calendar. Most efficient way of locking apps of your phone. Once locked, apps can be accessed only by entering valid user defined password. Phone can be locked completely, such that one can only answer incoming calls and nothing else.