Sorry if this is obvious, but does it use the same thing OpenBubbles does? What's nice about that is that it just hooks directly into Apple's servers, so doesn't require a connection to your phone or anything.
This is a good question. No, OpenBubbles impersonates a Mac and talks to Apple's servers. Tether connects to the phone via Bluetooth and asks the iphone to send/receive messages. OpenBubbles's technique is not supported by Apple, while their Bluetooth version is.
Besides messaging it doesn't do any of the other stuff Tether does (author, im biased).
Besides messaging it doesn't do any of the other stuff Tether does (author, im biased).