The THC in marijuana can differ greatly depending on the strain, making it hard to determine just how strong the weed you’re about to smoke/eat/vape is. Well, as the old App Store slogan goes, there’s an app for that.

Similar to the apps you’ll find that will tell you how much you’ve had to drink or determine how you’d be able to operate a motor vehicle in your current state of inebriation, a new app, Canary, uses a series of tests to determine just how effective that weed you ingested is.

First, you have to establish a baseline. That means you’ll run through the tests while you are completely sober and fully awake, to ensure you get the best results possible. The tests challenge your attention, memory, balance, and time awareness to determine your sobriety.

Once you’ve consumed your marijuana as you see fit, the first task involves memorizing a series of numbers that arrive one at a time on screen. You then have to say what the numbers were and the order they appeared in.

Then it’s on to attention. This test tasks you with seeing a graphic symbol, then picking it out of a crowd of other random symbols, Where’s Waldo?-style.

Next, a balance test that might be familiar to those who’ve undergone field sobriety tests. The app has you stand on one foot and cross your arms. A beep or vibration signals the beginning and end of the test, with your phone determining how stale you were in that period.

The final test has you count out loud for 20 seconds, while a timer does the same. This tests how aware you are of the passage of time.

After you’re finished, a canary appears with a smile or a frown to tell you if you’ve passed or failed.

Canary is available to download in the App Store for $2.99.