PDF Tools is an easy-to-use app to split, merge, compress, lock, unlock and rotate multiple PDF files in batch mode. Features include: Compress PDF - compress images in PDF document to reduce file size. Invert PDF - turn PDF document to "dark mode". Split PDF - remove unwanted PDF pages and save the rest pages. Merge PDF - merge unlimited PDF files to one single PDF file. Lock PDF - protect PDF with passwords and all kinds of restrictions. Unlock PDF - remove PDF passwords and all kinds of restrictions. Rotate PDF - rotate PDF pages by 90, 180 or 270 degrees.