Kitchenizer

Kitchenizer lets you generate a shopping list from a collection of recipes. You can choose which recipes you want to add to your shopping list, and for how many people. If multiple recipes use the same ingredients, the relevant quantities will be combined in the shopping list.
You can also add individual items to your shopping list, in case they're not part of a recipe.
If you happen to already have a few items at home, you can enter them in the app so that they don't appear in your shopping list.
Kitchenizer also allows you to share recipes, either publicly, or with some friends.
Lastly, Kitchenizer lets you send your shopping list to others. This can come in handy when someone else does your grocery shopping for you.
Don't hesitate to leave feedback!