You don't need us to tell you that apps have grown to become a core part of modern smartphone ecosystems. Android and iOS, the two major app-centric OS environments are growing in leaps and bounds, while a substantial part of Windows Phone 7's eventual success is expected to hinge on exactly how it matches (or betters) those guys on the app front. So, what better excuse than that to check out this concept golf scoring app from Redmond? Designed using Microsoft's favored Metro aesthetic, it really streamlines the user experience by employing "multiple touch targets [that] are spread out from one another" and distilling content down to large, easily readable data. We've got to say, it's hitting the right note with us, but do follow along after the break to learn about a few of the WP7 design quirks -- such as the drop-down system tray and the reason why rounded app icon corners are undesirable.