It is easy to use and had multiple options (merge, split, etc.)

PDFsam is an extraordinarily intuitive and invaluable tool we all need on our desktops since it provides us with many practical features for handling documents in PDF format, which is one of the most widely used. It is a great application that can be used on Windows, Mac and Linux devices, to mention a few, with excellent performance on multiple platforms.

This one is simple - Alternate Mix - The absolute best feature ever! It allows you to combine/merge multiple PDF documents while allowing you to reverse the pages of individual source documents if required. It also allows simple merging, splitting, rotating of pages, extracting, and some other features, and everything just works, every time. It even allows you to "drag and drop" your documents into the program window, and automatically uses the same source folder as the destination. Simply put - it always works, it's user-friendly and really simple to use, and it's fast. Go ahead, try it, you will not regret it.