User defined post access

Does anyone know of a plugin, or something, that will allow my users to select their posts’ visibility on the frontend? The site is set up so user’s never have to go to the backend. I’m using Frontier Post as my frontend posting form. This plugin supports the native WordPress visibility options (Private, Pending, Draft) but that’s not exactly what I need. I would like user’s to select individual users, as well as making it public or private.

Any ideas?

Thanks