Halvo: Caffeine Tracker

Your last coffee decides your night.

Halvo shows you how much caffeine is actually working in you right now — and tells you the point after which the next cup starts costing you sleep. Your personal cut-off.

Most caffeine apps count milligrams. Halvo works with the caffeine that actually reaches your system: it rises, peaks and fades. Halvo predicts how much of it is still there when you go to bed.

YOUR PERSONAL CUT-OFF
Everyone clears caffeine at a different speed. Halvo shows you the latest you can have a cup without too much of it still active when you fall asleep.

LOG IN SECONDS
Add coffee, espresso, tea, energy drinks, soda, mate or your own pre-workout in a few taps. Halvo sums it up automatically and shows how much is still working.

ON YOUR HOME SCREEN AND ON YOUR WRIST
The widget shows your level and your cut-off without opening the app — one tap logs your favourite drink. In the evening it switches to "lights out" on its own. Plus Apple Watch with a complication for a glance-and-go check.

SEE YOUR CURVE
Watch caffeine rise, peak and fade on a real concentration curve — and see exactly where you'll land when your head hits the pillow.

A MODEL THAT LEARNS YOU — HONESTLY (PRO)
With your permission, Halvo reads your sleep, heart rate and HRV from Apple Health and learns your personal caffeine half-life over time. Here's what makes it different: when the signal in your data is too weak to be sure, Halvo says so and keeps using the population value — instead of faking precision it doesn't have.

WORKS WITH YOUR WEARABLES (PRO)
Apple Watch, Oura, Whoop, Garmin — anything that syncs sleep and heart data to Apple Health. Halvo never connects to those services directly; it only reads what's already in Apple Health.

PRIVATE BY DESIGN
Your intake and health data are processed on your device. Halvo doesn't sell your data.

FREE & PRO
Logging caffeine, seeing your curve, using the widget and finding your cut-off are free. Halvo Pro adds the personal learning model and the nightly sleep analysis.

Halvo Pro:
• Monthly – $3.99
• Yearly – $24.99 (with 1 month free)
• Lifetime – $44.99 one-time (no subscription)

Payment is charged to your Apple Account. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period. Manage or cancel anytime in your Apple Account settings. Lifetime is a one-time purchase. Prices may vary by region.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://halvo.jnmcloud.de/privacy.html

Halvo is not a medical device and does not diagnose, treat or prevent any condition. It helps you make more informed choices about caffeine.