Google Project Fi is the answer for a fast and reliable cellular data service. It lets the user text, call and surf through their Google Nexus 6 device while controlling how much data they have to spend for a month.

Google Project Fi detects Wi-Fi connection fast to get rid of huge mobile data usage, Android Central reports. It chooses a local Wi-Fi network as its default connection and in case there's no connection available,  it will make use of cellular network.  Google has partnered with US carriers Sprint and T-Mobile's cellular for voice and data access whenever a Wi-Fi is not accessible.

It can swiftly change from one network to another without hassle and without the subscriber's intervention. In short, Google Project Fi chooses the network automatically to get stable connections. The trendsetting mobile network is also stepping a gear with its Wi-Fi Calling.  It offers a feature called  voice over WiFi (VoWiFi)," Forbes reports.

"For Wi-Fi calls, I made sure that I had no cellular network signal before dialing a number and that the feature was toggled on in Settings. Calls that were being patched through this method showed the name of the Wi-Fi network on the dialer. When consistent, audio was very clear, easy to understand and appropriately loud. There were instances, however, when audio cut in and out, but it didn't last for very long. All in all it remained relatively steady," claims CNET rep, who tested Google Project Fi in the San Francisco area for many days.

A subscriber can enjoy the service by fulfilling two things.  Get a Nexus 6 phone that you can order from Google or third-party retailers and ask for an invitation using a gmail address. Once you have set up the sign in process, you will have your own Google voice number.  The service provides unlimited calls and texting in the US, Wi-Fi tethering and unlimited international texting in the US and 120-plus countries for minimum monthly rate of $20 plus taxes and additional fees. For additional data plan, Google Project Fi charges $10 per gigabyte a month.

Google will eventually open the service to everyone without the need for an invite.  Unused data can be rebated to next month. However, when you use more than you paid for, you can pay the excess on your next bill for a standard rate of $10 per 1GB.  Have you tried Google Project Fi?