The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From Research Triangle Software:
The CryptoBuddy Secret Decoder Ring for the iPad uses a character substitution cipher to create a crypto-code that can be sent to your friends. For example, if you wanted to send your friend a secret message of HAPPY, after sing the Secret Decoder Ring you would get a code of YPKKC. Send this message to your friend and they can use their Secret Decoder Ring to decode the message HAPPY. Anyone without the CryptoBuddy Secret Decoder Ring will not be able to decipher the message. CryptoBuddys Secret Decoder Ring for iPad uses the same secret character substitution cipher as CryptoBuddys Original Secret Decoder Ring, so either version will decipher your message.