Formidable Pro PDF Extended is a Wordpress plugin that allows you to save/view/download a PDF from the front- and back-end, and automate PDF creation on form submission.
This is an updated version of the original, abandoned project.
Note: I forked this in March 2022 and have been updating and developing it. I've opened a few pull requests, which you can view under branches. You can also view the Wiki for updated documentation.