What are some alternatives?
When comparing PDFTK Builder and Appnimi PDF Unlocker, you can also consider the following products
PDFsam - PDFsam Basic, a free, open source, multi-platform software designed to split, merge, extract pages, mix and rotate PDF files
SysTools PDF Unlocker - PDF Unlocker software allows users to remove restrictions from PDF documents. Unlock PDF for copy, print, edit, sign, comment, etc., On any Windows & Mac OS. Also, remove known user-level password & owner level password security from PDF files.
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
Aryson PDF Unlocker - PDF Unlocker Software is a smart utility used to remove the locks from the locked PDF files without corrupting the data of PDF files. It is advanced software used to remove the multiple restrictions from the PDF file with ease.
PDF-Shuffler - PDF-Shuffler is a small python-gtk application, which helps the user to merge or split pdf...
iSafePDF - iSafePDF is a free open source PDF protection software.