Here is a non-exhaustive list of smartphone applications to facilitate carbohydrate calculation:
Carbs and Cal ($) : Provides images of various food and meal formats. Available in English only.
CalorieKing: Allows you to know the nutritional value of several foods. Also includes a database of dishes from American restaurant chains. Available in English only.
Cronometer: Allows, among other things, to know the nutritional value of thousands of foods and calculate the nutritional value of recipes. Available in English only.
Figwee ($) : Provides images of various food and meal formats. Available in English only.
Gluci-Check (Roche Diabetes Care France): A carbohydrate calculation tool with portion visualization on the plate.
MyFitnessPal: Allows you to know the nutritional value of several foods.
Nutriments Canada ($) : Allows you to know the nutritional value of several foods, with the database based on the Canadian Nutrient File.

Note: Diabète Québec does not guarantee the accuracy of the content of these applications.