Good info on Google Fi supporting iPad but looks like you still need to have a Fi Basics Plan.
Guess Google forgot to update their main FAQs with the bit about supporting non-Nexus Tablets with data-only SIMs.
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What you need to know
Eligibility: You can add another device by ordering a data-only SIM as long as you have service activated with Project Fi.
Cost: Compatible devices share the same data budget as your main phone, at the same rate of $10/GB. If you want to see how much your data-only SIM is using, check your data usage like your normally would. You’ll see a breakdown for each additional device.
Tethering: Tethering from a device with a data-only SIM isn’t supported.
Coverage: Data-only SIM cards provide coverage in 120+ countries. See our coverage map. You may notice some coverage differences from your main Fi phone. Coverage can also vary depending on your device.
Number of data-only SIMs: You can add up to 9 data-only SIM cards. You can also use the same data-only SIM card in multiple devices.
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