Science Interactives and Apps
Crickweb
Crickweb have many good interactive games and animations.
BBC Science Clips
These are interactive simulations that can be used with a whole class on a whiteboard or at individual computers.
The activities are organised by year groups 1 to 6 and are based on the QCA scheme of work.
Sheppard Software
Many beautifully presented interactives including health and nutrition on their website here.
Particularly good are the animal, plant and environment games and animations at their Kid's Corner here