You can add your signature to PDF documents by using Apple, Android or PCs. Kurt "CyberGuy" Knutsson shows you how to add e-signatures using your devices.

The Adobe Fill & Sign app is a free third-party app available on the App Store that provides a more polished and professional approach to signing documents on your iPhone.

Need to sign an e-mailed PDF document? Going through the motions of printing, signing, and scanning the document is tedious. Fortunately, there's a faster way to go about this process.

Gadgets How To Scan, Sign and Share Documents From Your Phone You don't actually need to get any other devices involved.

We show you how to sign digital documents on your PC or smartphone free of charge.

Sign with Google Drive on Android or iPhone The Google Drive app -- included on all Android phones and can be downloaded onto an iPhone -- includes markup tools that make it easy to sign a document.