It seems that all the products from Bagatrix have moved to a web based platform. This means that you don't have to download anything in order to use the service. However, there is a platform that handles basic math, one for pre-algebra, one for geometry and so on. To have access to all of them , you need to pay a fee of $19.99 / month or $99.99 / year. If you want to find out more about this matter, visit the official website.