Learn to Code
ScratchJr - kids can learn to code!
Virtual Fieldtrips
The Nature Conservancy - explore the coral reef in the Dominican Republic, a coastal temperate rainforest and the great forests of China.
San Diego Zoo - has free live cams of their animals including polar bears, elephants, giraffes, apes (and their new baby!), koala bears, tigres, penguins and pandas.
Other:
All The World - videos (available in Spanish and English) that explain how the world works and explore topics in science, nature, art and culture.