A program can determine whether to keep or toss leftovers.
The USDA has a mobile app called Food Keeper that can tell if food is still good to eat, based on the contents, when the food was put in the fridge, the fridge temperature and how long the food has been sitting at room temperature.
The software also has food recall notifications, preparation hints, and a food poisoning checker for symptoms of common illnesses after eating unsafe dishes.
The app is available on Apple and Android devices at the Food Safety website.
