"Contrary to reports, Google didn't become a mobile carrier with the introduction of Google Fi. Google Fi was launched to prove that a network-of-networks serves smartphone users better than a single mobile carrier's network. Patents related to Google Fi, filed in early 2007, explain Google's vision – smartphones negotiate for and connect to the fastest network available. The patent and Google Fi share a common notion that the smartphone should connect to the fastest network available, not a single carrier's network that may not provide the best performance. It breaks the exclusive relationship between a smartphone and a single carrier."
Google Fi has survived from the experimental stages to a full-fledged cell carrier, and now the company is taking it one step further.
Google's cell service, Google Fi (previously Project Fi) will now support a huge range of devices, such as the iPhone and the majority of Android devices.
Photos that Google filed with the FCC show the device inside and out.