The principle is similar to the Kelly kettle. Drawing air up through a 'chimney' for a funnel effect and better burning. But looking at the photos especially the FIRE-SPOUT-100 model it looks dangerously unstable with a frying pan on top!
What I am looking for or probably to fabricate over the next few months is a wood burning stove which regulates the burn like a log burning stove. Enclosed and reasonably airtight when erected; control of air inlet; light, folding flat; reasonable size for fuel; some form of chimney to aid draw; option for flexible pipe to vent the smoke out away from the fire.
The idea is to produce a light, portable log stove which can use fule more efficiently than an open fire; can generate heat for a longer period ( overnight hopefully); acts as a fire box to prevent heat damage to the ground (leave no trace etc); ability to cook directly on it; option to attach small enclosed oven box on top for baking. Not much then
There are several small stove models but only ones I have seen are made in the USA and not easy to get in Europe.