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 Springfeed S.M.B.A.:
PINShield is an easy-to-use PIN code manager that enables the user to remember numeric codes while also ensuring a high level of security.PINShield stores and protects your codes through a visual grid representation. You place your codes in a grid at positions that you will easily remember, fill the remaining grid with ramdom numbers and store the grid for future reference.PINShield stores the complete grid representation and has no knowledge of the placement of your numeric code. Your code is hidden in the grid and only you will be able to decipher it. This protects your code from theft both in the real and virtual world.