Project Fi is a service announced by Google some time ago. In practice, Fi Project is a virtual mobile operator developed by Google. The American company does not have any infrastructure designed to provide signal for phones, so mainly Project Fi is based on cooperation with three companies: Sprint, T-Mobile and US Cellular. Using the transmitters of these three networks will be possible in a dynamic way, and when smartphone is connected to Wi-Fi, you will be able to use your phone number in the cloud. This means that in the moment of connecting the device to the wireless network, we do not need the operator's signal to make calls or send text messages. Google has officially confirmed that test phase of the project has been completed and, moreover, Google decided to rebrand this project. After all changes, this project will operate under the name Google Fi.
To use Google Fi we need to pay 20$. This sum of money guarantees users unlimited amount of calls and text messages. Data packets have been priced separately, and their price is quite high, because for 1GB of data costs 10$. After using 6GB of data, subsequent data transfers in a given billing period are free. Google Fi in its full form will be only for a limited list of devices which were designed with the Google Fi in mind, and this list is available on the project's website. These devices for now are: Pixel 3, Pixel 3 XL, Pixel 2 XL, Moto G6, LG V35 ThinQ, LG G7 ThinQ and Moto X4.