Startup Idea : Weight loss App using social pressure

Loosing weight by using gm , treadmill etc..is not easy people lose motivation and give up . here is the idea to bring in discipline by peer pressure using an App . 1)Let user chose a group of people near by using gps . 2) pay a member ship fee of lets say 100 3) according to age and current weight of group , the app sets milestone run for everyday for each member 4) you run , the app measures the run . 100% completion of milestone you are safe else , money gets deducted from you and paid to someone who ran more in your group .5) as a group the overall 100rs remians constant the money just gets circulated between succes and loser .this is just a brief , let me know if you want partner to build this concept