A few weeks ago, I was on the First Ring Daily podcast with Thurrott's Brad Sams, and we discussed the rumors of an upcoming cellular Apple Watch, along with how much carriers might charge for the service. So naturally, that got me thinking about what the best plan for an LTE smartwatch would be.
The answer is undoubtedly Project Fi.
OK, let's back up a bit. Google's data-only SIM cards only support seven tablets, let alone a smartwatch, and even if it did support wearables, the phone service doesn't work with iPhones. This is true, if you go by Google's list of supported devices, which include an array of Pixel and Nexus phones.
But a Project Fi SIM card works with any GSM device; Google isn't blocking you like some carriers will. You might not get all of the might of the combined networks of T-Mobile, Sprint, and US Cellular, but at the very least, it acts as a T-Mobile SIM card. So yes, you can use it in your iPhone, Windows phone, or whatever else you want.
And to be clear, I've been testing out Project Fi on the LG Watch Sport, and it works wonderfully.
Now that we've established just that it works, what makes Project Fi better than alternatives is that you don't have to pay for an additional line. In fact, you don't even have to pay an activation fee. Google will mail you a data-only SIM card for free. You just pay for the data you use, which is part of the data plan that you already have with Project Fi.
The service charges $10 per gigabyte, and whatever you don't use is refunded. If you have a 1GB plan for the phone on the plan and you only use 500MB, you'll get $5 back. If you use 500MB with your phone and an additional 200MB with your data-only SIM, you'll get $3 back.
It might be hard to justify paying an extra few dollars per month for the additional line that any other carrier might charge you. After all, will you really get what you're paying for with the amount of data that you'll consume on a smartwatch?
The answer is that you'll probably pay more for a data-only line from your carrier than you would for the data that you'd use with Project Fi, and then your carrier will charge you for data on top of that.