iGo charger is not Apple and thus may work fine.
What I meant to say is: Apple chargers (iPhone, IPad, etc.) are non standard, i.e. they do have special circuitry (resistors between data and supply lines) such that an Apple device recognized it as being an Apple charger.
Non-apple-devices may get irritated by this.
The correct pinout is described at
https://en.wikipedia.org/wiki/USB#Charging_ports
You can verify this by measuring the resistance between the two inner pins in the middle of the usb plug. Should be zero.