The ease of use! It's really intuitive to navigate through menus - especially when you're new at it (which I was). We had several different food allergies in our family and this made managing them much easier than having paper printouts or Excel spreadsheets everywhere we needed something specific written down about someone with an allergy/sensitivity. There are some features like birthday reminders which could be more user friendly but overall everything works very well once set up correctly so there isn't anything bad here as far as functionality goes. Tracking allergens makes things safer around usernames / passwords etc too since they can have multiple people using their account without needing everyone else know what foods were eaten by who specifically (this has helped me immensely!).