Double PDF --Lightweight and Tiny PDF Browsing and checking tool Browse two PDF documents and check the difference Double PDF is an useful tool to browse versions of your PDF eBooks (with Many many pages) PDFs made by Keynote or other office applications KEY FEATURES Flip two PDFs in one action (forward/backward) Find difference with two PDFs (String compare -> Rendered Image Compare) Browse difference by image (blink each pages preview image) OPTION FEATURES Browse text differences by BBEdit or Text Wrangler, the most famous text editors in the world Interface Languages Japanese, English, REQUIREMENTS PDFs must not be encrypted