Following its acquisition in progress, Google already confirmed that it would add the Assistant to the latest Fitbit smartwatches, the Versa 3 and the Sense, and today, it has arrived as part of Fitbit OS 5.1. The update will roll out to the two health trackers starting today, and it packs a few more things on top of the Assistant: Automatic SpO2 readings at night without the dedicated watchface, new SpO2 clockfaces, audible Alexa replies, and more.

Google Assistant is a hotly anticipated addition to the new Fitbit OS, at least for those who prefer it over the already existing Amazon Alexa integration. Fitbit touts that it's the first company to offer a choice between the two assistants on a smartwatch, and we're willing to believe it — Fitbit is in a special place because of the pending Google acquisition. Once you've received Fitbit OS 5.1, you can switch to the Assistant in the Fitbit app, where you'll have to enter your Google account credentials to get started.

Alexa has also learned to speak with this update, something it hasn't been able to at launch. In a similar vein, you can now receive calls via the smartwatches' built-in speaker and microphone, and responding to text messages with your voice is now possible.

Automatic SpO2 readings are also a more than welcome addition. In our Sense review, we complained that you had to use a dedicated watchface for tracking SpO2 at night, a requirement that's thankfully seeing the boot in this update. Let's hope the new firmware improves the accuracy of the readings, which was another complaint we had. If you'd like to see your SpO2 levels at all times, there are now also a few new clockfaces to choose from.

Fitbit Os 5.1 is starting to roll out today, so check your Fitbit app to see if it's already available to you. As always, it might take a while until it hits everyone's watches, though. The update is limited to the Sense and the Versa 3 for now.