BBB emmc as mass storage for android phone through android OTG port

I haven't purchased a Beaglebone Black yet, because I want to know if it can suit my needs.

I'm wanting to make an app for a phone, android and iphone. I want that app to be able to access a folder and the files within it on the beaglebone black's on-board storage. Is this possible? I've seen a few posts hinting that you can access an sd card by utilizing the otg port on the BBB. Is this possible to do by going from otg Port to otg port? Also, if it is possivle, will the BBB be able to modify those files while the android phone has that info mounted?

I know this is several questions, I'm just hoping the BBB is up to the task.

Thanks