The Great Translation Game

You can import texts and not only copy but actively attempt to translate. You get immediate feedback. It's fun. It's challenging. You can track the number of words and sentences you've written. You can save challenging sentences, add notes, and review them later. You can save individual words and phrases and review those later too. You can use news articles, blog posts, Wikipedia articles, and create texts from Tatoeba sentences to practice a specific set of words or grammatical topic. It's the best resource to improve your writing, vocab, and production skills in another language.