If you’ve ever had a DWI, you know you don’t want another one. A second offense in New Hampshire means losing your license for three full years, and a third offense means losing it indefinitely. Luckily, as the saying goes, there’s an app for that. In fact, there are several iOS and Android apps designed to keep you from getting behind the wheel when you’ve had a few too many.

BAC Calculators

The simplest sort of app for drinkers is the blood alcohol content (BAC) calculator. These programs do just what they promise: they calculate your blood alcohol content and let you know if it’s safe for you to drive. Most of them ask you to provide physical details—height, weight, gender, age—and a list of what you consume over the course of an evening. It’s only an estimate, but these apps can give you a sense of how much alcohol is in your system at any given moment. Some even have an element of fun to them. EndDUI includes several games which test your ability to focus.