I'm old style, pen and paper for me.
I just write down most of the foods I eat with the macro breakdowns, and then write out a daily meal plan.
I usually stick with the same calories and macros per set meal, but just change the foods sometimes when I feel like something different.
Must use a food scale for accuracy.
It can seem complicated and confusing, even frustrating at the start when trying to get the numbers to work, but after a while, it becomes very easy through practice.