If you have already uninstalled the app and installed it again you should receive notifications to allow Bluetooth. If you never received those notifications then please do the following to make sure that you are allowing access to the app:
1. Click on Settings
2. Scroll down to find either the Quiet Punch Play or Quiet Punch A.I. app
3. Select the one you are having trouble with
4. Make sure that you enable Bluetooth (see the picture)
5. To test connection especially in the Quiet Punch Play app, click Daily Punch Counter and see if it connects automatically.
6. Remember to turn on your sensor press the red button once. The sensor then stays on for 10 minutes and then turns off if there is no punch activity.