The Workbook Maker PDF Plugin is a free Android plugin developed by U-Shipps. It is intended for use with the "Workbook Maker" app and allows users to incorporate PDFs into their workbooks. The "Workbook Maker" app is a free app that enables users to create their own workbooks.

To use this plugin, users must first install the "Workbook Maker" app. The plugin is licensed under GPL V3 and the source code can be downloaded from the developer's website.

The plugin is based on MuPDF, a lightweight PDF and XPS viewer that is designed to be small and fast while still providing high-quality rendering. MuPDF is known for its speed, accuracy, and support for a wide range of file formats. Overall, the Workbook Maker PDF Plugin is a useful tool for anyone who wants to incorporate PDFs into their workbooks.