But it's paid app.
But not all your forum user's can purchased the app.
Monthly bill? There isn't a monthly smartphone bill, unless you're stupid enough to get a contract.
In the U.S., most use the subsidized phone process of the companies - ergo, paying $399 for a $899 iPhone. Overseas most buy the phone outright and then just pay what we in the U.S. refer to as Off Contract... but that avoids the point that no matter what - you ARE paying a monthly stipend (in some for or another) for the use of the service.