Estimate caffeine in your system.

What's left by bedtime.

Two numbers sit at the top of the app: the caffeine estimated in your system now, and the amount projected for your bedtime. Below them, one curve shows every entry adding up and wearing off, from three days back to a day ahead.

Pinch to zoom, drag to look back, and tap the curve to read the level at any moment. Change your bedtime and the projection follows.

The estimate adjusts for the age, weight and sex you enter. It's a model, not a measurement, and real metabolism varies a lot from person to person.

Estimates only. Not a medical device. Individual metabolism varies.

Your month, day by day.

The calendar shades each day by how much caffeine you logged, so heavier days stand out. Tap any day to see its entries.

Under the grid: your total for the month, entries, days logged, average per day, highest day and average per entry.

Goals you set yourself.

Choose the kind of goal: at most, at least, or a minimum gap between caffeine days. Count it in milligrams, entries or days, per day, week or month.

Each goal shows today's progress and keeps a history, so you can see which days and weeks you hit it.

Relix doesn't recommend an amount of caffeine. Goals are numbers you choose. Talk to a healthcare professional about what's right for you.