HexRinger is currently a free app for the Android-powered smartphone, allowing you to designate the kind of areas for your phone to be in silent mode upon entry. You will need to rely on the simple map interface and tap on hexagonal sectors to delegate them as “manner-mode off zones.” Set and forget is the key phrase here, and the good news is, HexRinger will not overtax your battery since it relies on your handset’s cell and Wi-Fi signals rather than GPS to determine its location. Location checking intervals can even be set to 2 hours, making it a form of backup, although by no means should you use this as your primary ringtone determining factor – that should always be done manually.