Even with an Academic Support class, a student should be studying at home on a nightly basis. The more times a person interacts with the material, the better chance they have at learning and retaining the information. They will also be better prepared for their tests. If your child says they have nothing to do, they should be doing the following:
reviewing (rereading) the material they worked on during the day
rewriting or typing notes from their classes to help with learning the material
creating flashcards to help study learning targets, vocabulary words and concepts. Someone then could quiz them with the cards
reading (it's amazing the assignments they will find to work on once they've been asked to read for 30 minutes)