Typing Speed Monitor shows you statistics on what you type, and how often you type aspecific group of words.
The Typing Speed Monitor extension records how fast you type while you are actively typing. Active typing is the time you spend typing and does not include any breaks longer than 5 seconds that occur between keystrokes.
The Typing Speed Monitor extension will show you how fast you type when you are off doing your normal day-to-day stuff, how long you have spent typing, what characters you have typed most, and provides you with a keyboard visualization that tells you statistics about each of the keys you have typed (you mouse over keys to get more information about them).
This visualization can be switched between showing you how fast you have typed certain keys to how often you have typed certain keys.