char280 - When 140 char isn't enough. Tweet up to 280 characters.
amphetype - Advanced typing practice program
Word Counter - A simple, beautiful word and character counter
TypingMaster - Learn touch-typing technique, and improve/increase typing accuracy and speed.
Wordcounter for Google Docs - A real-time word count and milestone markers in Google Docs.
Type Fu - Type Fu is an app that will teach you how to type fast. The right way. On Mac, Windows and Chrome OS.