Hi there -
Great news is that we already have one for the iPhone, iPod and iPad. You can track what you eat, calories, weight, exercise all towards your goal to maintain or lose weight. It's really cool, and free. :)
You can also track on your phone or on our site, and as long as you are logged in with the same user name and password, both will stay update as the app syncs to the site, and vice versa.
http://itunes.apple.com/us/app/my-diet-diary-calorie-counter/id414169919?mt=8 or download it from our site - http://www.medhelp.org/land/calorie-counter-app
It's free, and check out our other iPhone apps - Sleep on It, My Cycles, I'm Expecting, Moody Me, and Pic Healthy. All are available in the App Store, and you can read more about them here - http://www.medhelp.org/health_tools The
apps are about halfway down the page.
Please let us know if you have any questions.