Demos Graphing Calculator
A free online graphing calculator from desmos.com
Khan Academy Science
Khan Academy is a great online resource to help students study or expand their understanding of a variety of subject
Phet Interactive Simulation
The PhET Interactive Simulations project at University of Colorado Boulder has developed a vision for next-generation PhET sims. This vision leverages new technologies to extend access to PhET simulations across platforms, to increase customization options, to enhance data sharing capabilities, and to support integration with diverse educational products.
BioInteractive is a great site from the Howard Hughes Foundation. At BioInteractive, you can find award-winning multimedia resources, including apps, animations, videos, interactives, and virtual labs, to bring the excitement of scientific discovery into your classroom. Their rich video resources range from a series of short films on evolution, hosted by an award-winning author-scientist, to lectures on the brain given by a Nobel-prize winner—all supplemented by teacher guides and classroom activities. Their team members include scientists, artists, and educational experts.
Learn.Genetics is a great resource from the University of Utah for learning and doing more in depth into the field of genetics and molecular biology. They have many interesting videos, interactives, and visuals for learning genetics and molecular biology.