Here is another clever chair that promotes active sitting. The Balance 1 Fitness Chair works as a balance training stool, foam roller, and yoga wheel. It lets you rock, swivel and move to improve your core stability and balance. You can use this stool for lunges, stretches, and various yoga poses.
When you are done exercising, you can flip this stool to massage your spine and open up your shoulders and chest. You can find out more about it here.