Разработчик приложения Blood Alcohol Computer / Breathalyzer: Darren Gates
This is a FAKE blood alcohol content tester (breathalyzer) for entertainment purposes only.
The iPhone owner sets a fake BAC value. Then, a friend blows on the screen like a breathalyzer. Press "Show BAC" to see the blood alcohol content.
Of course, the iPhone has no such ability. The value shown is the value you initially entered. It sounds silly, but it may deter someone from driving drunk.
Someone who is drunk may not realize that the iPhone can't do this anyway - they'll probably believe you! The professional design of the interface makes it more believable.
You should input a value higher than the legal limit to drive to convince someone that they shouldn't drive.