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 Department of Innovation, Industry, Science and Research:
As business moves, we move with you.This is the official iPhone application for the Australian Government's principle business resource, business.gov.au. You can now access essential business information and resources in the palm of your hand using business.gov.aus FREE iPhone application.When you download our iPhone application you can: keep up to date with the latest business news search for Australian Business Number (ABN) information using our ABN Lookup tool find information on a wide range of business topics including licences & registrations, taxation, employment, home-based business, importing & exporting and many more customise your application to your preferred business topics add news feeds from your favourite websites More features coming soon!