The % in the app is about the relation between protein, carbs and fat for the total calorie amount.

The calorie amount for protein, carbs and fat per gram is not equal. 1 gram of protein/carbs is 4 calories whilst 1 gram of fat is 9 calories.

Let's say you pick Keso 4 % and 100 grams of that.

This contains 93 calories:

protein 12 grams (12 * 4 = 48 calories) 48/93 = 0,516/ 52 %
carbs 2.1 grams (2.1 * 4 = 8.4 calories) 8.4/93 = 0,09 / 9 %
fat 4 grams (4 * 9 = 36 calories) 36/93 = 0.38 / 38 %