Fitbit Charge 4 update adds new on-device functionality

Fitbit coming to users of its wearables in the United States, but not all of them were available right away. Starting today, Fitbit Charge 4 is getting a new functionality that will make it easier for users to check certain health data directly from their wrists.

According to the , Fitbit Charge 4 users will finally be able to estimate their blood oxygen saturation (SpO2) while they sleep from their fitness tracker. Up until now, checking SpO2 levels was only possible from the smartphone via the Fitbit app.

Another change included in the update is probably just as important, but …