This simple tool is to allow merging 2 PDF files that came from scanning a two-sided document up and down. You scan one document on one side then you scan the same document on the other side. You obtain 2 PDFs. The first PDF has the odd pages. The second has the even pages but they start for the last page.
This tool merges the 2 PDF files and reorder the pages correctly.
The tool is using unidoc that's why it's license is AGPL to be compatible with unidoc.