I made a big response to someone else's comment. I just don't believe that final food temperature is function of temperature where the food touches the pan. However, where your product might shine is where water content determines one very, very important aspect of a finished product, the sear or crispiness.
Let's take the mushroom for example. If the pan's surface temperature is too low or their are too many mushrooms in the pan the water comes out of the mushroom and prevents it from being caramelized and browned. Yes, there is a lot more than just the negligible about of sugar in a mushroom when it browns and I would have been more accurate to use an onion to describe this but I'm sticking with the mushroom. What is caramelization? It is cooked sugars. Caramelization starts at 320 degrees F so if the pan doesn't get past 212 degrees F because water is being released from the mushroom.
There are two ways to brown a mushroom. One, start with very, very high heat, brown the mushroom's surface, then lower the heat so the inside cooks. Or, second, use low heat, let the mushroom release all its water, then after the water evaporates raise the heat. This is the same for caramelized onions. One way is to use high heat which even leaves the inside of the onion crispy[1], and the other is to use low heat for a long time until the water is evaporated[2]. Also, most recipes for ground beef in pasta sauce say to brown the meat on med-high before the moisture comes out, however, adding water initially, and then cook it until the water evaporates before browning it is a valid approach also.
I'm not sure the usefulness of this app in determining the proper final temperature. Plus, anyone can stick a $7 thermometer into a piece of meat. However, many people and professional chefs make the mistake of putting way too much food into a pan. Your app might be a ton more useful warning cooks that their pan is below or above the proper cooking heat. Sea scollaps are the worst for this. There is a huge difference between cooking 4 u-10s or 8 in the pan at the same time because the water being released cools down the cooking surface temp to the point that they are boiled instead of pan fried. However, with sea scallops raising the heat to the pan or changing the cooking duration isn't a solution. The solution is have the right amount of scallops, in a right sized pan, at the right cooking temp.
I think this app can be much more useful in helping cooks learn to maintain the proper surface temp of a pan for wilting spinach, cooking mushrooms, making fried rice, searing scallops, ect. than telling when the food is done. Perhaps, telling when food is done can easily be done with a cheap thermometer but using the right surface temperature is the hard part of cooking.
[1]: http://www.lemonythyme.com/wp-content/uploads/2012/07/Carame...
[2]: https://corkandspoon.files.wordpress.com/2012/05/crock-pot-c...