The Plexdata's Converter Utility is nothing else but a tool to unzip base-64 strings and to extract PDF data from base-64 strings.
The software has been published under the terms of MIT License.
The latest release can be obtained from https://github.com/akesseler/converterutility/releases/latest.
The master branch can be downloaded as ZIP from https://github.com/akesseler/converterutility/archive/master.zip.