I've tried to use BLE Scanner and 'LightBlue', I've also tried to pair from the system settings but don't get that option. I can connect fine.
With a pair of Bluetooth headphones I can connect to a device from the system settings and it transfers automatically into the my devices.
As per the Accessory Design Guidelines for Apple Devices link, it seems to suggest that I need to communicate with AT command and responses with the host device (e.g. iPhone). I'm working out how to get that running.