It’s not always easy to figure out the healthiest foods to buy at the supermarket. Now, there’s a way to have a nutrition expert’s tips any time you need them, for free.

The Shop Well app lets users scan barcodes on food labels to determine if the product fits their personal dietary needs. It can help manage nutrition needs for those with conditions such as diabetes, high blood pressure, lactose intolerance, or celiac disease.

Users make a personal profile on Shop Well, based on age, gender, eating habits, and food restrictions. Shop Well then scores food options from zero to 100.

A high, green score means the product matches the user’s diet. A yellow score advises eating that food with caution, and a low, red score indicates the user should avoid that product. If the food doesn’t match the user’s needs, Shop Well can suggest alternative foods that are a healthier choice.

All scores are based on guidelines from the U.S. Food & Drug Administration (FDA), U.S. Department of Agriculture, and the Institute of Medicine.

For more information, visit shopwell.com.