This app has the most comprehensive database on Histamine Intolerance of all and is still being maintained and updated from time to time. The support team is open to suggestions for adding foods and are swift to respond.
Good thing about this app is that it gives not only a hint to the amount of histamines in a food source, it also gives information about histamine activation, effect on DAO and more and also tells why that is. Something that is lacking in all other apps I've purchased.
This one replaces all others.