Also the people that have the hardest time completing their goals tend to be people with ADD/ADHD and basically every study shows that these people are not motivated by rewards.

Also with an app like this, there are no good controls. The only motivation is not losing your money, so you just fake a victory to prevent any loss.

In fact, if there is anyone not meeting their goals and losing money .. the motivation for many people will be to buy into many challenges and collect free money by faking victories.