Starfall is a collection of computer games aimed for young children. They’re designed to be educational as well as engaging.
The program emphasizes exploration, play, and positive reinforcement—encouraging children to become confident and intrinsically motivated. Starfall is an educational alternative to other entertainment choices for children and is especially effective for special education, homeschooling, and English language development (ELD, ELL, ESL). It is widely used in schools that serve children with special needs and learning difficulties.From starfall.com
Although not free, Starfall is inexpensive and offers bulk prices for teachers and schools so multiple children can use it in their classrooms