I purchased this app before becoming a member of team athlean-x as I wanted to see if this can help me achieve the look I wanted. Boy was I impressed. The shuffle feature is fantastic. Just when you think your core is strong, the shuffle feature proves you wrong. Thanks to Jeff the creator, for making this available to anyone who really wants to challenge their core. I love the reward you get with this (a balanced washboard look) and the ability to adjust the difficulty on the fly with the shuffle.
Now please add the 31 scariest ab exercises, as posted on YouTube and the good old ab wheel as an equipment option!!!
Aka flash.
MaxRain about 6 Pack Promise - Ultimate Abs, v2.0