WordCounter by Christian Tietze (@ctietze) does one thing, and does it well:

It counts the number of words you type in registered applications and displays the total on the menu bar.

Most writers I know use several different software tools while writing, like nvAlt for notes, Byword for short pieces and Scrivener for the big things. But each of these has a separate word count (if at all). WordCounter brings them all together in one. Perfect!

Available direct at http://wordcounterapp.com.

Follow the author as @hiltmon on Twitter and @hiltmon on App.Net. Mute #xpost on one.