In my practice I often need to obtain client signatures on documents very quickly. In litigation, they must sign under oath their pleadings (Complaint or Counterclaim, Motions, etc.) and discovery responses (Answers to Interrogatories, Response to Request for Admissions). Once in a while a client needs to drop what he or she is doing to receive an emailed document, print it, sign it, and scan it back to me. 10 years ago it was iffy whether the client would even have ready access to a scanner. These days, luckily, most do, which makes it easier for me. However, I also always look for ways to make my client's life easier. It occurred to me that there should be a way to sign a document on your phone, and of course, it turns out there's an app for that.
I have been using Sign Easy for a few weeks now. http://getsigneasy.com/ They have an app for apple devices, web and android phones. You pull up the document, sign it with your finger and then email yourself the document. So far, it has been working great.