API to add data to a users private posts?

Hello –

Not sure if this is way out there or not but I’m wondering how difficult it would be, or if there is some plugin, or combination of plugins, that would allow an app developer to have their app users be able to save data, from their app, to their BuddyPress profile (either as a private post/activity/document).

For example you develop a mobile app that allows users to input reviews of movies.

The user writes a review in the app and saves it. At some point the user is asked if they’d like to “post” that review on their movie community – which I’ve created using BuddyPress.

I saw some API plugins to sync data going in the other direction – from my site to FB, or Twitter, etc…but how difficult to provide app developers with an api so their users can sync data to my site?

Thanks for any advice!
Rob