A fitness cushion relieves back pain and trains your stomach muscles, because it forces you to stay in motion all the time. Core balance ftw!
I've started a new training besides my main profession, which not only increases my daily stress level, but also takes away even more time for fitness activities. In total, I'm spending 2.5 hours sitting in my car every day. That's a lot. So why not do something productive while standing at a red light or sitting in a traffic jam?