Know your buzz.
The cute caffeine tracker that knows when your last safe cup is. Scroll through a day with Beanie — he's already watching you.
Three steps between you and a good night's sleep.
Pick from a 90+ drink catalog — delicate teas to menacing energy drinks.
"What are we sipping?"
Real half-life math tracks every milligram — tuned to your personal sensitivity.
Science, but make it cute.
Get your last-safe-cup time and bedtime warnings before it's too late.
"Tonight's sleep is side-eyeing that last cup."
Feed him caffeine. Watch him metabolize it, live. (He forgives you.)
All quiet in here. Beanie is basically decaf.
He burns it off on a 5.5 h half-life — sped up so one second ≈ 13 minutes of bean time.
400 mg = the meter's edge. Beanie starts sweating way before that.
Caffeine doesn't leave when the cup does.
Caffeine has a half-life — every few hours, your body clears half of what's left. For most people that's around 4 to 7 hours1, depending on how fast you metabolize it. JitterBox defaults to 5.5 hours and lets you tune it: fast metabolizers 🐇, slow metabolizers 🐢.
That 2 PM latte? Half of it is still buzzing around at ~7:30 PM, and a quarter at 1 AM. This is why "I can sleep fine after coffee" is usually a lie your Tuesday self tells your Wednesday self.
JitterBox also personalizes your daily limit: roughly 5 mg per kg of body weight2, or the 400 mg general guideline3 if you'd rather not say. Then it works the math backwards to find your last safe cup — the latest moment a drink still clears before bedtime.
1 Average adult half-life is ~5 hours, but genetics, pregnancy, and some medications stretch it a lot.
2 A common research heuristic for a moderate daily intake. Not medical advice — Beanie is a bean, not a doctor.
3 The FDA's oft-cited "generally not associated with negative effects" number for healthy adults.
JitterBox runs your half-life math backwards from bedtime and names the exact minute. After that, it's water and vibes.
Still ~48 mg on board at a 10:30 PM bedtime — a third of a latte, arguing with your pillow.
The whole privacy policy fits in four sentences.
🔒 No accounts. No cloud. No tracking. Not even analytics.
Everything is computed on your phone. Your logs live in local storage, exportable any time, deletable in one tap. There's no server to breach because there's no server at all.
JitterBox is free, has no ads, and tracks nothing. It runs on exactly one fuel source. ☕
☕ Buy Beanie a coffeeThe four questions everyone asks.
Yes — v1 is free. Beanie works for exposure (and the occasional espresso).
On your device, and only your device. You can export everything as JSON any time, or erase it all in one tap.
Someday. Beanie is currently monogamous with iOS, but he's open to growth.
Because he's cute. Next question.