I recently purchased the Osmo Mobile and successfully paired an iPhone 7 as the main device. I would like to know if you can then pair another different iPhone 7, as when I tried to do this it worked with the opening the camera but didn't give me the option to pair the new device and the bluetooth wouldn't connect so other than using the camera to view none of the functions worked?

Osmo Mobile can only connect to one mobile device at a time.
If you would like to connect to another iPhone, please make sure the Bluetooth of other device has been turned off.