There are a lot of apps out there, some with costs up to $5.99.

Amonst the free apps, Glucose Buddy seems useful. As a physician, any app that can record the blood glucose before meals and create graph to show trends that can be used to manage diabetes is very helpful.

Diabetes Log is another free app, and it allows the use to keep track of blood glucose, carb intake and medication usage. It does not have a carb counting function though.

Go Meals is an app by Sanofi Aventis which provides nutritional information on food including food purchased at restaurant chains and grocery stores nationwide.

Hope this helps!