Providing expansion content to Android apps
<p>I plan on providing a free app in the Android Market with some sample content from various "expansion" content packages that I intend to sell separately. These expansions would contain no executable code, just additional static data like sounds and images. </p>

<p>I've researched this a bit trying to see how this could be done. I've come up with a few different possibilities:</p>

<p>1) <strong>Separate stand-alone app per expansion</strong>: Each stand-alone app would contain that expansion's content and would require nothing else to be installed. Though this would work for some applications, I'm not really considering this as a solution because I ultimately want an app where if the user has purchased multiple expansion packs, they can browse through all of them in-app.</p>

<p>2) <strong>Selling a "data only" app</strong>: I've seen a few apps actually do this. You purchase and install an expansion "app" from the Android Market that installs no application at all (i.e. - it's not displayed on your Application list). Somehow the actual app finds the expansion data and uses it. I'd like to find an example of how to do this exactly.</p>

<p>3) <strong>In-app Purchase</strong>: I know that Android provides an In-app Purchase API, but I'm not sure exactly how this would work. I assume that if I went this route I would have to provide the content myself on my own web server or something. This seems both very cool and a big pain to do.</p>

<p>So, my question is, what is the best way to do this? Are there any pros/cons of each method that I've missed? Are there any other methods that I've missed completely?</p>
