1)   PDF Split-Merge 1.1
PDF Split-Merge is used to split files by pages, you can split the file into single pages or save every a few pages as a new file, it also can be used to merge multiple PDF files or selected pages from one or more files into a PDF file.

 2)   PDF Merger 2.50
PDF Merger is used to merge(append, concat) pages from the Adobe Acrobat PDF files to create a new PDF.