Traditionally, signing a PDF is an exercise in frustration. Because most desktop PDF-editing software is a digital dumpster fire, it often seems like the most straightforward solution is the manual approach — print the document, sign it on paper with a pen, then scan or photograph it and attach the resulting file to an email to return it to the sender. But that's only the easiest method if you don't consider using your phone, because there are any number of apps that'll do it all digitally, without any need for a printer, camera, dead tree, or pen.

There are several apps in the Google Play Store that you can use to sign a PDF.

Read More