Not a dumb question – it isn’t necessary. However, I tend to not eat enough protein and I am generally anemic, so it helps to have something keep track of grams of protein, mg of iron, etc. I find it sort of motivating, because it’s satisfying to enter something that makes my stats look good. Map My Walk is fun because it shows you the change in elevation, etc. and is a general indicator of the difficulty of the course. Both these apps tend to keep me on the right track (although the holiday season has been a disaster in terms of healthy habits . . . ).