How does one Plone Add-on access Data in another add-on?

@austinsdoe if you are a total novice to Plone development, I don't recommend you try building this except possibly with Plomino as @djay suggests, but even then you might still be lost conceptually. You would be best off finding someone who has development experience with Plone (anyone in this thread or see Plone.com/providers) and preferably Bika.