No worries, we'll get you paired up again.
To start, now that you've factory reset, you should be seeing a 4-digit code on the screen of your device (if you don't, plug it into the charging cradle to charge up, and it should reappear). That's your pairing code, and you'll need that to re-pair the device to the app.
Now open the Striiv app on your phone/tablet. You should still be signed into your Striiv account, but if not, go ahead and sign into your account like usual. Now, tap on the Device tile (the one that has a picture of your device on it) and scroll down until you find Deregister Device. Tap on this, and follow the on-screen instructions -- you do want to de-register.
Now, you''ll re-pair your device to your app. Tap the Menu icon within the Striiv app -- the three horizontal lines in the upper left corner of the app screen -- and tap Device/Pair Device. This will take you through the pairing process, which you completed when you first paired your device to your phone/tablet. Make sure you have your Striiv device plugged in and charging, and the Bluetooth and wi-fi on your phone/tablet are on.
If you run into any trouble during this process, please email us at firstname.lastname@example.org with details and we'll help you out.