After you have installed and opened the App, do the initial setting required for setting up of your user profile and other features such as location access, notifications, and data syncing for the App.
When done, go to Setting -> Devices and drag down the App interface to start detection process for the AGPtek Smart Wristband. Please make sure Bluetooth is enabled while the phone is searching the tracker. Also try to keep both the tracker and phone close to each other and check both devices have sufficient battery power.
However the App was unable to locate the AGPtek Smart Wristband where the tracker did not appear on the App. The App unfortunately can't be used to pair the AGPtek Smart Wristband and the iPhone 6 Plus over Bluetooth LE.