You’ve been emailed a document, and you have to sign it and send it back. You could print out the document, sign it, and then scan it back in and email it. But there’s a better, faster way.
This article shows you how to quickly add your signature to any PDF document, saving it as a standard PDF file that can be read anywhere. You can do this on Windows, Mac, iPad, iPhone, Android, Chrome OS, Linux — whatever platform you prefer.
I’ve been using Master PDF Editor on Linux for a while, mainly because I often have to paste signatures in (and Okular does not do that at all – yes really odd) but I now tried Xournal and yes it does all I need as well as much more. Maybe now, too, Google’s GDrive will also allow the form filling and signing (it’s not mentioned in this article as it’s quite a new feature).