For Windows Phone you can search for the app online (on our Windows Phone Store) and get the URL. In Windows 8 it isn't as obvious, so here is one way.

Here is one way:

  1. Visit the Windows Store from Win8
  2. Search for the app
  3. Click on the app
  4. Then Charm and select Share
  5. Select email and from there Copy the url. The UI won’t show the full URL but you can still copy it
  6. Paste to your heart’s content