How to calibrate pool length on Fitbit

We had to wait a while, but we finally got ourselves a waterproof Fitbit. In fact, there's now a bunch of Fitbits that can survive a dip in the pool and the sea. The Fitbit Flex 2 was the first to get some waterproofing love, then came the Ionic and Versa smartwatches - then the…

from Wareable