The Fitbit app is compatible with most popular phones and tablets, as well as Windows 10 computers. To verify that your phone or tablet is compatible with the Fitbit app, go to www. Choose a link below depending on whether you prefer to set up your device with the Fitbit app or with Fitbit Connect. Tap the notification and follow the on-screen instructions to set up your device. To set up your Fitbit device with the Fitbit app:. If you have trouble, see Why can't I set up my Fitbit device?