Locklizard Safeguard Viewer for iOS is a FREE app that lets you view Locklizard secure PDF documents (PDC files) on the iPad and iPhone. Safeguard Secure PDF Viewer supports PDC files protected with Safeguard PDF Security and Enterprise PDF DRM.
An installation video can be found at https://www.locklizard.com/Videos/Viewers/ios-viewer-install.mp4