I currently pay Verizon $30 a month for the same service. If I were to purchase the app and download it to my phone/pc, does this mean I can cancel that plan with Verizon and just use it for free once its purchased?
In theory yes, but it is a direct violation of the VZW contract, so if they catch you, they can and may terminate your service. All depends on if you are willing to take the risk.