After years of all day sitting in front of computer for work it started to show it's bad impact on my posture. I did lot of research to correct my posture. I found lot of things on the market for that reason. Having all the belts, gadgets etc. did not help! Then found out real and important thing for better posture is being aware of it.
Posture Corrector app will make you aware of posture with tips at the time interval set by you.