NeeView - Display two images simultaneously
Wondershare PDFelement - All-in-one PDF editor
Soda PDF 3D Reader - Read any PDF document like a book using our patent pending 3D technology!
Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
ACBF Viewer - Comic book reader.
Foxit PhantomPDF - Edit PDF files with our feature-rich PDF Editor. Download Foxit PDF Editor to convert, sign, scan / OCR & more. A speedy PDF Editor alternative to Adobe Acrobat.