MyFitnessPal

Price: Free (in-app purchases) from fave.co/2RI2IJx

Counting calories and nutrients is a huge pain, but MyFitnessPal makes it easy. It has a huge database of common foods and you can just scan the barcode of almost any packaged food item to add it to your daily count. You can do all this with the free ad-supported app, but a £7.99 per month Premium subscription kills the ads and gives you lots of control over custom macronutrient goals. This is the most full-featured and easy-to-use app we’ve found for keeping track of your diet. And keeping track of what you eat and drink is the first and most effective step toward being healthier.