We make hundreds of food decisions every day. When you get down to the nuances of very specific decisions - 100% juice or whole fruit for breakfast, adding spinach or romaine to a green salad, almonds or walnuts - there is a great tool to help you maximize nutrient dense choices.
It is not an app or a software package. Simply search two foods in your Google toolbar by typing "compare x to y". A chart comes up, thoroughly comparing the two foods. The data is based on the USDA National Nutrient Database for Standard Reference (http://ndb.nal.usda.gov/), which contains over 8,000 foods.
So, spinach or romaine? Spinach gives you double the potassium and triple the calcium, both nutrients of public health concern, according to USDA. Those are nutrients of which the average American is not getting enough. I'd choose spinach.
Almonds or walnuts? Almonds get the nod - lower in saturated fat, higher in monounsaturated fat and higher in fiber (another nutrient of public health concern) and protein.
Tonight we are having burgers for dinner. Swiss or cheddar? Does it matter? Type "compare Swiss cheese to cheddar cheese". Swiss is slightly lower in calories (maybe it's the holes?). Swiss is also much lower in sodium. Swiss gets the nod from me.
Go explore a little. Compare butter to margarine. Compare honey to sugar. Compare apples to oranges. (Yes, you can do that.)
Get savvy and make factually based food decisions.