The most popular scale that people use with Gyroscope is the Withings Body+ (also called Nokia for a while, when they were acquired by Nokia briefly).
It costs about $100 and connects to wifi for automatic* syncing. It can estimate your bodyfat percentage using the conductance of your skin. This is sometimes a useful metric, but not extremely precise. It can very well differentiate between someone who is 50% bodyfat and someone who is 10%, but the exact measurement can bounce around quite a bit.
The benefit of having a nice scale in your own bathroom is the ease and frequency of measurements, generating a strong signal from data that can bounce around otherwise. Tracking at a consistent time of day (ie. every morning) and with a consistent amount of clothing helps further.
Fitbit also makes a comparable wifi scale.
A cheaper not-wifi but Bluetooth option is the Renpho scale, which can be found on Amazon for around $20-30. It requires a bit more work to sync, or manual entry into Gyroscope, but can provide comparable results with a little less luxury.
When shopping for a scale, you may want to double-check that it can measure bodyfat, especially if losing bodyfat is a priority. WIthout that, it is sometimes a mystery if you are gaining/losing muscle or bodyfat.
Most scales with an app will export to Apple Health, enabling the data to go to Gyroscope.
However, just tracking weight is better than nothing. Weight measurements from any scale can be easily entered in the app from the + button. This works well for low-tech scales, like the ones found in a gym locker room.
* Sometimes it can get disconnected and needs to be reconnected in settings.
For more details about all the common devices & integrations, check out the Hardware Guide:
Another scale roundup is available at: