Stoners sure are getting more responsible in the lead up to the inevitable end of weed prohibition.

There’s been some concern that as states decriminalize bud, smokers are going to menace the roads with their blurry-eyed, carefully slow driving. The National Organization for the Reform of Marijuana Laws is getting out ahead of the concerns by funding an app that works as a “digital breathalyzer,” letting weedheads know when they’re too high to drive.

My Canary, just $4.99, lets iPhone users measure balance, memory, and time perception with a series of tests, like standing on one leg or hitting buttons whack-a-mole style. After, you get a red, yellow, or green light so you can make an informed decision about your driving ability. Since THC leaves your system a lot slower than alcohol, breathalyzers alone can have a hard time getting an accurate reading, though expect cops to be increasingly armed with those gadgets on patrol.

Business Insider reminds Seattle and Denver residents not to confuse this service with the Canary weed delivery business. Branding is important these days and apparently marijuana businesses are putting a bird on it.

Photos via Getty