Adobe EchoSign

Adobe EchoSign is an official Adobe app that lets you use a digital signature on any document, as well as send and track documents for others to sign digitally.

With Adobe EchoSign, you can sign any document anytime, anywhere. The signature can be done either with a fingertip (which is a bit inaccurate) or with a stylus (considerably more precise).

From the Adobe EchoSign app, you can also send documents to other users to sign. In addition, you can sync the app with Google Drive, Box, or Evernote so your documents are always backed up.

Another interesting feature is the option to use your own Android so another user can add his signature to a document from your screen, in person.

Adobe EchoSign is a great business tool that can be very useful if you don't want to carry around lots of folders and papers, which are much heavier and less manageable than a simple Android device.