I think this is a great idea! I agree with Claire McLeland's idea to involve people that the community respects. One possibility would be to offer training to grandma's or teachers or other people that are already respected within the eyes of the community. Then an app could be created to help advertise when classes will take place. For example, a group of respected community members come together and are taught about eating healthier. They could even be taught how to make their traditional foods a little bit healthier. With this knowledge the trained community members could offer classes that they think would be interesting to their community.
In terms of having respected members/organizations offer this within communities, it would be interesting to go through sources that the community already gathers around. From personal experience I know that it is common in Hispanic communities for Church to be a strong tie within the community. And if people feel that they have learned new recipes or techniques for living a healthier life, they could even have weekly or bi-weekly dinners where all of the trained members come together to cook a healthy meal for the community. At the same time, they could hand out pamphlets to everyone who comes on quick tips to healthier eating and that point out how their meals have been carefully prepared with their health in mind. Another option would be to have conversation cards at the tables that could lead everyone to engage in conversation about leading healthier lives.
I like the idea of integrating it into online streaming Alper Yaglioglu suggested! Also, a few years ago I visited the Smart House at the Museum of Science and Industry at Chicago and it had a bike powered tv in the kid's room. Maybe another function would be to target a part of the component specifically at parents who want to see their kids go outside more. And I think kids would gladly embrace it as an extra challenge in the game, and try to outdo their friends with the "rare" or "cool" merchandise they can get with the extra points.
I like the 50/50 idea that Burt A suggested. Personally I was thinking that I would get this app in order to veganize some, but not all of my meals. Some of my favorite Colombian traditional dishes just would not taste the same without the meat, but I have veganized or vegetarianized others in the past for some of my friends. I think a simple but useful add-on to this app would be able to track how many meals you veganized, perhaps in a calendar of some sort. This would not really be for people who are fully vegan, but rather for those who are transitioning or just trying to have a little bit of extra healthiness in their lives.