The plate has won a 2016 National Parenting Product Award, a 2016 Family Choice Award, and was featured by the National Parenting Product Awards.
Yet according to research on feeding kids, pressuring kids to eat "healthy foods" along with using food as a reward are linked with dis-inhibited children's eating patterns.
Having 3 kids, all of who went through their picky eater stages, I know what it feels like when they don't eat. But rather than pressure them, trick them, coerce them (with the promise of dessert if they eat their dinners), or encourage them to ignore whether or not they're full by having required portion sizing, we kept offering them healthy choices, encouraged just "one bite to be polite", allowed fruits and vegetables to their hearts' contents after any meal, involved them in both menu planning and cooking, and didn't ever link dessert with how much or what they ate for dinner (and yes, we have dessert at least once weekly and usually more).
And while your mileage may vary with the strategies we employed, if your kids are turning their noses up at what you're serving them, the gamification of the clean your plate club strikes me as something that could generate some unhealthy, unintended, consequences.