Help Please!

So this site is for helping and sometimes I hope you will comment with something you need help with. But today I need your help.

So I am in cub scouts now and need a really good behavior reward system. I am in a pickle so it needs to be really good. Keep in mind that I have a boy who can't have sugar so it needs to be either a mix of something or no sugar. Also I want it as an individual thing. From what I have heard these kids are little devils. Any idea would be great!