The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From American Ballet Theatre:
American Ballet Theatre brings the worlds greatest dancers to the worlds greatest stages. Explore our performances and discover our dancers with the official app of American Ballet Theatre.Features include: Find upcoming performances and casting Learn about our ballets and our dancers Share with your friends via email and social networking Add performances to your calendar Discover the performance venue, either on the web or on a map Find performances featuring your favorite dancer Identify dancers you saw on-stage with our photo galleryAll inquiries regarding the ABT app for iPhone and iPod touch should be sent to email@example.com.