Chrome: Lingualy is a language-learning extension for Chrome that learns how good you are with a language, and then recommends texts online for you to read to test your skills.
At first, you'll take a few quizzes to see how good you are with the language you want to learn. As time goes on, Lingualy recommends new articles based on your reading level and tests you on vocabulary as you go along. Lingualy learns the type of articles you like and recommends similar articles around the web to test you with.
It's all about grammar, but it's still a useful and relatively unobtrusive thing to introduce into your language learning habits.