IntelliDrink PRO: Blood Alcohol Content Calculator
Here is another app that helps you monitor your BAC to avoid silly mistakes while drunk. The IntelliDrink PRO lets you set a limit and get notified when you fall below or exceed it. It helps you analyze your alcohol consumption habits.
The app calculates your absorption of alcohol over time. IntelliDrink PRO takes into account your age, weight, gender, and stomach content. It comes with Apple HealthKit integration. You can try this app for under $3 at this time.