Who knew that smartphone owners were suddenly such temperate drinkers? Just days after Alcohoot unveiled its take on a phone-friendly breathalyzer, Breathometer is here with its own way to watch our tipsiness. The namesake, FDA-approved gadget will plug into the headphone jack of an Android or iOS device and warn if our blood is too alcohol-rich, all while staying small enough to fit on a keychain. Plans are underway to eventually let soused users hail a taxi from the native app. The Breathometer won't be available until we're at the height of summer party season, but it should be cheap enough to eliminate any excuses: its Indiegogo campaign is asking for just $20 to secure a Breathometer alongside a pledge, or less than a good night out.