This exercise for your abs is a variant on the classic crunch and is ideal for working intensively on the upper abdomen. Rest your hands on your quadriceps, work is focused on the upper part of the rectus abdominis.
App Store: https://itunes.apple.com/app/apple-store/id426364250?pt=292213&ct=YT%208%20Min%20Abs&mt=8
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Windows Phone Store: https://goo.gl/ijjVdH