Licenses are valid for life, including software updates. New features may cost extra if you want to use them.
PhoneBooster licenses are coupled to the hardware, so they can only run on one device. If a device breaks, you can ask us for a new license for your new hardware.
You can verify that PhoneBooster works in your environment without a license, the non-licensed version inserts the sound of a ringing telephone in the audio occasionally, but is otherwise fully functional.