The 1.5.1 version of PDFCombo for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The program is included in Productivity Tools. The most popular version of the application is 1.0.
Pdfcombo_v1.0.3.zip is the common file name to indicate this program's installer. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This free software for Mac OS X is an intellectual property of Onekerato. This free software is developed for Mac OS X 10.6 or later.
From the developer:
PDFCombo is an app to combine multiple PDF files. Unlike other apps, PDFCombo preserves the Table of Contents (TOC) in the combined PDF. It can also add a new top-level TOC entry for each contributing PDF. This can be useful to keep a complex TOC neat & tidy, or to add a TOC item to demarcate contributing PDFs.
You may want to check out more Mac applications, such as PDFMergeThing, Apimac Clean Text or Gordon, which might be similar to PDFCombo.