Readdle has released a major update to PDF Expert for iPad with support for the Retina Display and improved PDF viewing features. The new Retina Display support renders PDF documents with sharper and more readable text and annotations providing a paper-like reading and annotating experience. PDF Expert 4.0 also adds support for embedded media in PDF documents allowing users to listen to audio and watch videos within documents directly in-place. PDF Attachments and PDF Portfolios are also now supported in the latest version allowing users to more effectively organize their PDF files and transfer entire collections of related PDF files as a single portfolio document. PDF Expert 4.0 requires iOS 4.3 or later and is available from the App Store for $10.