iOS: Fitness trackers are pretty easy to come by these days, but not many of them help you use the information they gather to get you to eat the right foods. Fuel My Run is a pretty simple app that tells you when to eat and drink.
When you open Fuel My Run, you can choose between different training methods and distances, and the app will remind you when you need to eat or drink. That's basically it, but if you're gearing up for a marathon or you're just bad at remembering to drink water when you're out running, Fuel My Run can keep you from hitting that wall.
Fuel My Run ($1.99) [iTunes App Store]