The idea behind JakToGo is that airline passengers can avoid extra baggage fees by wearing their luggage. It goes far beyond stuffing pockets with gear. The JackToGo isn't stylish, but it is functional.
The manufacturers claim that you can carry 10 kilograms in it, but I suspect that you could probably carry more, so as long as the material and stitching hold up and you can physically move around.
Will airlines let you wear it? Well, this video shows a man wearing it while clearing the terminal gate.