While our app is currently only able to sync directly with Google Fit and Apple Health, there are third-party apps that help you sync your activity tracker data (e.g. as Fitbit and Galaxy Watch) with Google Fit such as FitToFit and Health Sync (+ more).
How this works: when you install one of the sync apps linked above, your Fitbit or smart watch will then track your activity as usual and then automatically send it to the third party app. That app will then forward the activity measurements to Google Fit, allowing them to appear in the app where you can get rewards for them!
Have an Apple device? Check out this article for how to connect to Apple Health instead.