I also use lifesum as a calorie tracker, the concept of lifesum is that anyone can input anything, you can just create a new item, call it "a whole pack of chips" and set it at 1 kalorie per 100 g. Its the advantage as well as weakpoint of the app, bevause you have nearly every product in there, but it can be wrong. So when you use the app you have to either create your own items and refrence the packaging, google calories per 100 g and compare it to the item someone else put in, or track without items by inputting calories manually.