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 MSE (Australia) PL:
The 'CheckIt' app is a tool for delivering checklists to anaesthetists. It is intended to be used for: The checking of complex equipment systems (such as anaesthesia delivery systems or heart lung machines); The provision of guidance during the management of anaesthetic crises, or Mundane tasks such as the description of an anaesthetist's preferences.The free version differs from the paid version in that: Only three checklists can be maintained by the user. Checklist templates cannot be downloaded from the website.Users of the full version are provided with a tool for downloading a variety of medical checklists from the applications website. These checklists can be used as templates for the development of individualized checklists.