Serial over USB communication on IPAD with custom device

[vid_s21]

Hi All,
I have a requirement like this:
I have a device which is a very basic embedded system that has a serial port.
I need to develop an app that should run on IPAD and connect to my device serial port via a USB cable.
I need to know what should be the approach.
Also what should be the license to be procured for this, if I need to get my device detected on the IPAD for serial communication via USB cable.
The device is cannot be given to third parties or outsourced. So if the serial communication requires driver development also to be done , then what should be the SDK? What is the first step in this regard?
Please help!

Thanks,
Vids