It is absolutely essential that you add this option. There's a multitude of people using smartphones with very limited internal storage.

This is absolutely a must-have feature. If one of your target audiences is people in developing regions with limited connectivity, the ability for them to use a cheap phone or tablet (which typically have minimal internal storage) with an SD card is essential.

Please implement this. Many (more affordable) Android devices only have limited internal storage, but room for a large, cheap MicroSD-card. If courses can be saved on the SD-card it would be great for users all over the world, but especially those in developing countries.

I agree, this definitely needs to be done

I'm with everyone else, would be nice to choose where to store videos

That'd be great!

A long awaited feature, make it so!

please make it happen

If you are able to root your android device you can use the app link2sd to move the khanacademy app to your sd card. It costs a buck or two but works great and with any app.

Another plug for this feature... given the cost of a micro SD card, vs. the cost of buying a higher end device (phone, tablet, etc.) with more internal storage, it makes sense to be able to download to the SD card as much as possible.