I've just added a comprehensive set of websites useful to learners outside of class. While chosen to assist adult students at the pre-intermediate level, a number would also be valuable to use with younger learners.
The sites cover all macro-skills, activities, quizzes, flashcards and other vocabulary resources, self assessment, typing practice, and text-to-voice assistance.
To access this set of sites and previous suggestions listed for younger learners, go to "Learn" then "Learning Help".