iOS and Android
Video Link: http://www.youtube.com/watch?v=0NqMrlUlxAE
Excellent application that allows the user to input whatever you eat.
Users can easily use phone camera to scan barcodes to pull up nutritional facts. A digital food scale used along with this program would offer very accurate carbohydrate counting.
Overall Impressions from Around the Web:
Mixed reviews with some iOS users having problems with recent updates. Other users extremely enthusiastic about previous version and hoping for fixes to recent problems.
Calorie Counter by FatSecret (Android)