Are you up for the challenge? Start with one sit-up on day one, and then add one every day. The Add-A-Day Situp Challenge is an app that will track your progress. You will be amazed of how many sit-ups you can do in a year. The Add-A-Day Situp Challenge App will allow you to share your progress with your friends and the world.
下载地址：iTunes 或者AAP STORE 下载
