A free program for Android, by SmartApps38.
You can use this app to easily convert your DOCX files to PDF. You don't need to install anything else as it is a standalone app. The best thing is that it works on any device and platform. You can also choose to convert your DOC files to PDF. It is very easy to use and the result is really good.
To begin with, you need to select the document to be converted. This can be done by either choosing the document from your device. Once you have the file, you need to select the output format. You can do this by selecting the PDF or the DOCX format.
