UnityPDF - UnityPDF lets you merge, split, divide, rotate, protect PDF files and more.
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.
PDFsam - PDFsam Basic, a free, open source, multi-platform software designed to split, merge, extract pages, mix and rotate PDF files
PDF24 PDF Creator - Create PDF and convert documents to PDF for free with the free PDF24 PDF Creator.
Clipperly - Convert, edit or optimize your files online. More than 400 different formats supported among documents, images, spreadsheets, ebooks, archives, presentations, audios and videos.
Merge PDF (by Smallpdf) - No file limit, no ad watermarks - a free and beautiful tool to combine your PDF files exactly the way you want it.