PhET is a very good platform that offers free interactive simulations to help students develop a an informed understanding of a variety of phenomena covering science, physics and math. These simulations come to life via the use of graphics, interactive controls, sliders and radio buttons. Students can easily manipulate its intuitive interface and even get animated feedback and responses as they navigate their way through simulations.
Students - please use your own personal email address here and not the one supplied by your school. For security reasons school emails block external messages.