Don't accept blank or already done guesses.
Add comments to the code.
Add the markdown extension to the README.
Add Bundler support and a README.
Rename some routes to be more RESTful.
Add a games archive page.
Add accuracy stats.
Autofocus the letter field for better experience.
Show a different page for my current game and others.
Show the found letters.
Allow to start a game.
Change the way to load classes.
Refactor word adding.
Add page to add words.