Are there any objects children could make that are easier? If children dont need much help building the object, you would save on human resources.

You could make a list of materials available locally in one particular place and objects that would make sense for those people.

Great visual communication, Lego was very useful in this idea. You definitely covered well this challenge and I think children will benefit from it a lot. The sustainability part is the best, these countries should have those concerns too, too bad these are the most affected by our lack of sustainable behaviour.

Great initial research, it is true that in times of desperate need, radical new solutions should be applied. I wonder tho, if something via mobile phone will be engaging, other types of media could be added, so that communication isn't only made by sound.