Site offering a variety of apps that teachers can use to create activities and that students can use on their own. Intended for EFL, but would also be useful for other languages in some cases.
Limitations: As of 6/9/2016, no new registrations are allowed, although the site can be used without registering.
Arch Chinese is a premier Chinese learning system crafted by Chinese teachers in the United States for Mandarin Chinese language learners at K-12 schools and universities. Designed from the start specifically for English speakers who have no or little knowledge of Mandarin Chinese, it offers a rich set of features with a slick and easy-to-use user interface.
Satori Reader provides carefully curated, level-appropriate content with which to practice and grow.
With thoughtfully annotated articles spanning a variety of interesting subject matter and a unique system that presents content in a manner appropriate to your knowledge, it bridges the gap between the controlled, textbook Japanese that most students start with and the wide-open world of real-life, native communication.
Videos with English subtitles. Click on unknown words, see their translation, add them to your library for further study and practice with people from all over the world.