Applause is an application that displays app icons on your desktop. It downloads the icons of the most popular applications for Mac and iOS and it places them on top of your wallpaper. The icons are semi-transparent, so they don't totally block your wallpaper. You can't interact in any way with the icons, which I think is very absurd. I can't find a reason why I would want to stare at app icons instead of a wallpaper.
When you run the application for the first time, it starts downloading the icons and putting them on your desktop. By default, it downloads the top paid app icons from the Mac App Store, but if you venture into the settings, you can change this to either the top paid, top free or top grossing apps for iPad and iPhone as well. From the settings, you can also set the app to launch with your system and you can use a slider bar to adjust the opacity of the app icons, also called AppTrends within this application.
Applause needs an active Internet connection to work because it needs to connect to the App Store servers to retrieve icons. The app runs on the menubar, from where you can access its settings.