I second this; seems like the developer is making it harder than it needs to. Bluetooth is so universal and, not to mention, a two way protocol which opens up a world of possibilities.
One way protocols are preferred to minimize energy consumption. Even the lithium batteries in phones and tables have to be replaced after you recharge them regularly (I suspect that even leash mode is receive only).
So DreamLover Labs opted for one time use batteries because they can hold a charge better. It's only function is to punish the wearer.
Beyond that you need a local device such as the remote or the USB transmitter. Though having its own SIM port would bypass a phone entirely.