Oceans are a great place for learning. It might be learning about tides or about erosion, it might be learning about ecosystems or coral reefs. It might be learning about the animals of the ocean big and small. Here are a number of apps for when your students are studying about the ocean.
A well made flash resource that introduces the features of a forest and our responsibilities to look after them. The resource is generic enough that it is useful for forest locations from around the world.
http://ictmagic.wikispaces.com/Science