If you're ever launching an app on the app store don't make the rookie mistake of only including screenshots of your app in your listing.
People browsing the store glance at the images FIRST before bothering to read the description of the app.
If you're only using screenshots of your app, 90% of people have no idea what your app does and they'll just go on to the next one.
Take the time to make professional looking banner ads in your listing. Look at your competition for ideas.
This will greatly boost your installs/sales.