You start off in the Diary (the starting page in the app). Select the meal you want to add food to. On the next page you find the icon for the barcode scanner to the right in the search bar.

1. Click on the barcode scanner icon in the top right corner.
 
2. Scan a barcode. Done!
 
You can track the item by clicking on "ADD TO DIARY".

Note! In case there is not enough light, please click on the little flash icon in order to activate the light of the phone.