You can digitally sign a PDF in several different ways, including Adobe Acrobat, Apple's Preview app, and mobile apps, among other options.

Instead of turning toward a fax machine or snail mail to put your John or Jane Hancock on the dotted line, do this instead. Want to sign your name from an iPhone digitally? Mac? PC? Android? It's now ...

You can sign a document on your iPhone through the Mail app, where you can use the markup tool to add your drawn signature.