UPDF - UPDF is a free, unique, productive, and delightful PDF editor for Windows, Mac, iOS, and Android.
NeeView - Display two images simultaneously
calibre - Ebook manager, viewer & converter
ComicFlow - ComicFlow is an iOS app that allows you to read comics by opening .cbr or .
OverDRIVE - Make workspaces and sites automatically from Google Drive
ACBF Viewer - Comic book reader.