This app is pretty new so it doesn’t have as many critics as it should but I promise you they will come. I find this app incredibly dangerous because it is sneaking Orthorectic habits into people that are well intended.
The consequences of “clean eating” and the rating based on the Nutri score system which has been approved recently in Europe but is being debated as we speak because of its inaccuracy.
More about it here (not based on science regardless of what the app makers say):
https://www.dw.com/en/opinion-why-europe-should-abandon-the-nutri-score/a-62922313
When you consult the Toxicology Education Foundation (TEF) for another perspective. “It is illegal to sell unsafe products,” said Jay Gooch, the vice president of TEF. “We don’t believe companies would knowingly do so at the risk of the public and investor relations issues and lawsuits that would inevitably occur.” We know that even when ingredients may be only plausibly problematic, they are eliminated from the market and replaced with safe alternatives.
Gooch also referenced the toxicologist’s mantra, “The dose makes the poison.” While a hazard is defined as the potential to harm, the exposure might not be high enough to do so. And he pointed out that the average person is not qualified to evaluate scientific research.
It’s hard to argue with any of that, but many people might not be comfortable with how long it takes the scientific community to reach a consensus. For example, the FDA asserts current BPA exposure levels are safe for humans, but that hasn’t stopped many people from seeking out BPA-free products.
The reality is that this app promotes ‘clean eating’ behaviors which are proven to lead to orthorexia nervosa.
And here’s the thing, bacon may be unhealthy in excessive amounts for someone that needs to watch their salt or fat intake but it may be the healthiest food for someone needing calories and to replenish electrolytes. No food is inherently good or bad, it depends on the individual needs and the amount. Anything in excess can be unhealthy but anything in moderation should be allowed as part of a varied diet.
Did you know that when the gluten-free craze became a fad among the public that wasn’t celiac, many mumble years ago thank goodness, though still, some people linger on that; moms started feeding their babies only rice instead of the three cereal baby food because of its wheat/gluten content, after all, no mom wants to poison their babies with evil gluten 
The consequences of such nonsense ended up in babies poisoned by high amounts of arsenic which are naturally part of rice. There are many chemicals that are naturally part of our food and they are not only safe but oftentimes added to foods to fortify such foods because it is healthier to consume enough of them.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429976/
Avoiding some components of our food can lead to overconsuming others such is the case of rice for babies. It’s much better to have a diet as varied as possible in the amounts we need to support our activity levels, age, and personal needs and preferences.
If you decide to use this app, please be careful.