Schoolfriend.co.uk, the brainchild of a London couple, is, they claim, the first interactive learning system providing individualised tuition for five to 11-year-olds on the Internet.
In less than a year, Amanda and Stephen Argent had set up the website using pound;2 million of private investment. Now it has become a computer program used by more than 300 state schools.
The Easington and Seaham education action zone in the North-east has adopted the program and negotiations are underway with 13 other action zones.
Schoolfriend.co.uk also has a link on the Department for Education and Employment's website.
The couple have four daughters and Mrs Argent said: "Teachers need to go at a pacewith the national curriculum, taking children quickly through lots of topics.
"But sometimes it can all be taught far too fast without consolidating the fundamentals. If a child hasn't got to grips with fractions, for instance, it can colour their whole attitude to maths."
The maths and spelling sections of the website are running, and are available to schools free of charge. By the end of January nine subjects will be available.
If 10 parents from one school decide to subscribe to the website for 99p a week, that school is given a free computer.
The program initially assesses a child's level of learning and then sets exercises that match it. They can be downloaded, thus keeping telephone bills to a minimum.
Completed exercises are then uploaded for marking. If the program detects a child struggling, it will offer a tutorial, and will not move on to the next topic until the child has mastered the first.