For those who came in late, Google Fi was first called Project Fi, then Google Fi, and now it's "Google Fi Wireless." It has its third logo -- an "F" styled to look like sideways signal bars and in Google's trademark rainbow colours.

Google is providing a free trial mode and harnessing the power of remotely configurable eSIMs to give anyone with an eSIM-compatible phone a seven-day/10GB free trial of Google Fi. That makes it easy to run around and test coverage.

Google Fi is a mobile virtual network operator (MVNO) -- a mobile reseller -- of T-Mobile's network.

Google said that during the trial it will provide a new Fi number to try out on your phone, but your current number will still work.

During the trial, you can choose between Fi or a current network whenever you're calling, texting, or using mobile data.

You'll need to enter a credit card for the trial, and after seven days, you'll be automatically billed on a $50 "Simply Unlimited" plan. Google notes you can cancel immediately (this is just one or two taps inside the app) and will still get the seven-day trial, Google said.