displaying and submitting a student_annotation assignment from a custom mobile app

[arickatz]

Hi all,
I am looking for a way for displaying and submitting a student_annotation assignment from a custom mobile app that we developed.
I saw that this is not covered via the APIs.
We have our own pdf annotation logic in our app and i was wondering if there is any way we 
can pack our annotation into the same format used in the pdf viewer used in the mobile apps.
I saw that the mobile app uses the PSPdfKit library, do their annotation have a standard or proprietary format that we can tap into?
Is there any other way to overcome this limitation?

Thanks, Aric.