The meals and ingredients you put in What Dinner? are saved in the local storage of your device. This means that What Dinner has no access to your data. It also means your meals cannot be restored when you switch phones or when you accidentally delete your meals.
What Dinner? has no access to your contacts, your photos or anything else on your device.
What Dinner? doesn't ask personal data of you. You do not have to create an account to use the app, you remain anonymous when using What Dinner?.