Please check the following:

• Make sure your ColorReader / ColorReader PRO device is fully charged / your ColorReader EZ has full batteries, then delete the ColorReader app from your mobile phone and restart your phone.
• Uninstall and reinstall the ColorReader app from the AppStore / Google PlayStore
• Make sure that the ColorReader app has the permission to access the location services from Android / iOS, as only this will allow the ColorReader app to use the Bluetooth functionality of your mobile phone.
• Next launch the ColorReader app, make sure your ColorReader / ColorReader PRO / ColorReader EZ device is still powered on to connect the ColorReader app to your ColorReader / ColorReader PRO / ColorReader EZ.

Please also read this when you use an Android mobile device:

• Turn on your device and go to the Android Bluetooth® settings. Make sure your ColorReader / ColorReader PRO / ColorReader EZ is listed as the device available to sync up with. Don’t try to sync the ColorReader / ColorReader PRO / ColorReader EZ using the Android Bluetooth® settings.
• Now launch the ColorReader app, make sure your ColorReader / ColorReader PRO / ColorReader EZ is still powered on to connect the ColorReader app to your ColorReader / ColorReader PRO / ColorReader EZ.