It automatically moves phones between traditional cellular networks and the WiFi wireless networks inside homes and businesses. Once on WiFi, you can still make calls and send texts. And you can pay for all this in small, flat, monthly fees—avoiding the sort of inflated, strings-attached pricing that so often accompanies our cell services.

But the most interesting perk is that the service uses two different wireless carriers—T-Mobile and Sprint—and you don't have to pick between them. As you move from place to place, Project Fi will not only move you from cellular to WiFi and back again. It will move you between T-Mobile and Sprint, depending on whose signal is the strongest in your particular location.

"The unique thing is that you're no longer tied to a network.