jPDFFields allows your application to get and set field values.
Dimer Beta - Simplest way to write and publish beautiful docs
iTextPDF - iText offers flexible tools for PDF creation, editing and inspection.
Content Editor 2.0 by Surfer - Content Editor is the most advanced content optimization tool that allows you to write and grade your work.
iText - iText is an intuitive and refined text editor with word processing completely rewritten in Cocoa...
Publish to WordPress - Publish content on WordPress right from Google Docs
RadaeePDF Master SDK - RadaeePDF SDK is a powerful PDF rendering library for Android iOS and Windows 8/8.1, WindowsPhone and Windows 10 UWP. RadaeePDF SDK can render, create, annotate, modify PDF files. RadaeePDF SDK can get and set PDF form and acroform.