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 TrustX, Inc.:
TrustX is an application that allows individuals to prove their identity using their mobile phone or tablet. It is a mobile authentication application which provides a number of different options for verifying an individual's identity: something you have (a mobile device), something you know (a PIN/passphrase), something you are (multiple biometrics such as face, voice, and palm matching), and somewhere you are (GPS). All of these factors can be combined to provide assurance that an individual is who they claim to be. TrustX can be used to securely authenticate a wide range of activities, from authorizing online banking transactions to authorizing access to medical records.