We've all had days of mainlining Americanos to make it through work, before jittering like a chick with separation anxiety the second you try to get to sleep.
And, now and then, we're guessing that isn't a huge problem.
Less alright is a caffeine habit that's having a real and prolonged effect on your sleep every night – meaning you wake up groggy, neck a couple more espressos, and so continue the clever, clever cycle.
Because everyone's body metabolises caffeine differently, it's not much use to limit yourself to such-and-such amount at such-and-such a time, according to someone else's experience.
By analysing the data that you input on what you drank, when and tracking your sleep patterns, it traces your caffeine levels to tell you when you're wired, when you're getting there, and when your weary body is de-caffeinated enough to kip.
Made by the people behind the wearable tech products Jawbone and UP band, it doesn't require either – which if, like us, you're slightly terrified of turning into a cyborg, you'll be glad of.
Download it here.