CocoaBooklet is a software running under MacOSX, allowing you to generate booklets from various PDF files.This version is contains certain bug fixes and the help ans support feature has been improved.
Normally this program will optimize the use of pages. For example a single A4 pages will have 4 PDF pages printed on it , 2 on each sides (Landscape layout). You just have to fold the paper in half and start creating your booklet.
Note that this version supports the use of printers that can't a paper on both sides.