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 Blackmagic Design:
Control your Videohub broadcast SDI routers from your iPad!Videohub Control uses a familiar push button interface that's fast and easy to use. Simply tap a destination button to show the connected source, and then change sources by pushing any of the source buttons! If you want to lock a destination, then double tap! For more destination and source buttons, just swipe!Installation is simple, and all you need to do is select Videohub in your iPad settings to enter the IP address for your Videohub router. Be sure your iPad is on a wireless network that has access to your Videohub router first! To configure each interface button, just press and hold to select source numbers and icons.Check the Videohub router instruction manual on the Blackmagic Design web site for more information. www.blackmagic-design.com.