When you try to pair your ZeFit2 using a mobile phone, you must make sure that ZeFit2 is nearby.
If you still experience the problem:
- make sure your Bluetooth is turned ON
- make sure you have Wifi / 3g
- reset your iPhone
- if ZeFit2 happens to be "Connected" in your Bluetooth list, then tap on the blue icon at the right hand side, and then tap "Forget this device". Open the app and try pairing again