I dont know if anyones replied to you but...
If you want a flatter stomach do core exercises, they make your waist smaller - do planks!
Theres lots of different versions of them, but just the still ones like the pic work really well - 30seconds to 2 mins holds.
You can also start in a push up position, go down to the plank, one arm at the time, lift right knee up towards left shoulder (under your body, so across your belly) and then left knee to right shoulder, then back up to push up position and do however many you want really... start easier.
and i used to do a squat challange with bodyweight, but as many as i could every day and night, which i gained half an inch from in less than a month, now im doing different routines, at the moment its weighed deadlifts which are really good!!! So im not goin to join the challange, although i sort of wanted to, but it most likely wont give me results. Obviously i wnt post here again cos this thread is about the challange.
People keep in mind that if you dont have weights, dont do weighed exercise, cos you need to increase the weight every workout, or reps, or sets.... and you need to do bodyweight exercises first, to make sure youre doing the exercise correct, or you could seriously injure yourself... n if you want to increase your booty size you need to eat lots of protein...