Wonderbag
The Wonderbag is an insulated non-electric cooking bag designed by entrepreneur Sarah Collins and poverty activist Moshy Mathe to reduce the amount of fuel required in the cooking of food in developing countries. Instead of being placed on a stove for the entire duration of the cooking period, the food is instead initially heated to a boil (usually) and afterwards put into the Wonderbag, which acts as a thermal cooker to cook the food to completion, this makes the Wonderbag functionally identical to a haybox, making it also useful to keep the food warm.