Snailbox - Schedule your email at specific times and recover the time you're losing to your inbox.
globalquiz.org - Difficult, multiplayer and multi-language trivia game.
Inbox When Ready - Protect your focus... hide your Gmail inbox by default
HugeQuiz - test your knowledge with a variety of quizzes about everything.
Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.
ActionQuiz - ActionQuiz is an online website that lets you select a quiz and play against computer opponents to see which one of you is smarter.