I have had back issues for about two years now, and it causes me to not only be a fidgety person but I tend to have to look for different ways to sit comfortably. Anyone even without back problems knows that it can wear on your back after hunching over a laptop for any extended period of time.
This little cushion is meant to offer a comfortable way to lay on your stomach and type. It would support your frame and likely help with any back discomfort.
Unfortunately it's not available in the US or UK, or I would have ordered one the moment I found it. The only concern is that it wouldn't be steady enough to put on your bed or might be too wide for the average couch. Hopefully your floor is clean and comfortable if you intend to pick up one of these.