A global wireless system for Android mobile devices from Google that supports Wi-Fi calling. Users seamlessly switch phone and data service between Wi-Fi hotspots and cellular. Introduced in 2015 and initially offered via invite-only, the Nexus 5x, 6 and 6p were the first phones to support Fi, which can be purchased directly from Google. Fi piggybacks over the Sprint and T-Mobile cellular networks along with more than a million free Wi-Fi hotspots that are automatically used. A Cloud-Based Phone Number Subscribers are given a phone number that can also be used to make phone calls and send text messages from their tablets and computers via Wi-Fi or Ethernet. Fi Basics - USD $20 per Month With no annual contract, the Basic plan provides unlimited domestic talk, low international rates in 120 countries and unlimited international texting. Each gigabyte of encrypted data is an additional $10/month, and unused bytes are credited to next month's bill. Family sharing plans were not initially offered. See Google Fiber.