DigitWiz and the Windows Explorer Addon are written by XRayz Software and are completely free, no strings attached and contains absolutely no adware or spyware.

• DigitWiz
  Assists in one of life's annoying little tasks: converting those name-style alphanumeric telephone numbers into straight numbers for easy dialing.
• Windows Explorer Addon
  Adds a column to Windows Explorer details view that shows the extension part of a filename.