Has anyone used the app "PostureScreen" for the iPad or iPhone? If so, do you recommend it?

I found an app call PostureScreen that seems to be a great tool that I can use with my clients. However, the price is $20.00 and there are a lot of additional in app purchase options. My question is, if you have used this app, do you recommend it, and what does the $20 include without any additional purchases. Thank you!