Regulation Process for Add on Accessory to an Existing Medical Device

Background:
We are developing a mobile app as an extension to an existing medical device. The broader level features are:
- Mobile app in tablet to be used in OT.
- This application will control the settings of medical device
- This application will use image / video for conducting the medical procedure.

Quries:
1.For our Accessory , will it be considered as a Assessory or will it considered as a different device ?
2. The Regulations of that accessory is same like medical device, I mean do I have to follow the whole process for just that Accessory / For whole device or 510k only for that Accessory / The whole device?

Thanks You.

Hello.

I've attached the FDA's final guidance on mobile medical apps