[deleted] PDF Viewer is a GrapheneOS made app. The other apps such as Clock, Dialer, Gallery look rather dated as im sure you have noticed. This is because these apps are only receiving maintainance updates from Google. GrapheneOS will take the burden of overhauling these apps or replacing them. Its a low priority as of now, but i don't think it will take more than a year personally. When this time comes, im sure they will add some long awaited features to Pdf Viewer too, and a better UI.