How can I load resources from another app?

I'm developing an Android app for which we will be selling separate content in the Android Market. Since Android lacks an in-app purchasing model as iOS has, I have come to understand that this is the ideal way of selling additional content (but NOT functionality) for Android apps.

So the question is, how do I actually load raw resources from other Android apps, assuming that I know 开发者_如何学运维the exact name of the resource, app ID, etc.?

Content Providers are the standard way for apps to make their content available to others.