Adobe EchoSign

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.