There are a number of free themes for app promotion out there that look great, but are typically just one simple page with room for a screenshot, a short list of features and a link to the app store.
With this theme you get a great looking front summary page like other free themes (with an added area for gathering e-mails for apps in the pre-launch stage), but you also get a features page where you can add in any number of features and screenshots.
You can get the free theme here. Tweet required.
You can go here to see the theme in action.
A really nice freebie.