I use an app to keep track of my fast day calories. I find that it keeps me honest on fast days, and when I was starting out with 5:2 is really helped me learn about how many cals are in a serving of food. It sometimes surprised me!
Calorie counting can be a pain, but it has taught me that my servings pre 5:2 were too big.
The app I use is Australian Easy Diet Diary - find in the app store. It has so many Australian brands of foods, and the foods that we eat. You can also easily scan a barcode from a food pack, or enter in the details of a new food.
It also lets you store your recipes and serving size. I make a oat slice that is fairly low cal, and I can add all the ingredients of the recipe and the serving size (10 slices) - and whenever I have a slice all I have to do is tap.
Does anyone else have a fave app for their tracking?