Some foods answer in hours.
Some take a week.

One window cannot hold all of this. So there are four.

Most food diaries look at the few hours before a symptom. That works for a stomach that reacts to lunch. It is useless for a leg that swells four days after something, and worse than useless when one window averages the fast reactions and the slow ones into a single number that describes neither.

Tideline reads from same-day out to two weeks, and lets you move that line yourself. The lens you are looking through is always named on screen.

Fifteen seconds, or two taps.

A diary you stop feeding tells you nothing. That is the whole design constraint, and everything optional sits below the fold where it cannot slow you down.

Tideline says what today is still missing, once, in one line, and then leaves you alone. No streaks. No notifications. No daily check-in to fail.

If you are testing one thing at a time, say where the line was.

Four weeks without a food and four weeks back on it is not a question a rolling month can answer — it averages the two halves together and reports the middle. Mark the day each stretch began and Tideline reads that stretch on its own, then shows how often symptoms came in each.

What it will never do is run the schedule for you. No countdowns, no washout timers, no week three of four, no nudge to move on. You mark a phase when you decide it started, and the app records that you said so. It is your protocol; the app only keeps the notes.

A sorted list of suspects. Not a verdict.

Diet advice is full of confident lists of culprits that are not your culprits. Tideline waits until it has enough of your own days to work from, shows how much evidence sits behind every row, and says plainly when it does not know yet.

"Followed 5 of 7 times, about twice your usual rate." Rows without enough behind them say so instead of inventing a number. And when a food turns up in nearly every meal you log, Tideline says that too — there is almost nothing without it to compare against, so its place in the list would describe your logging habits rather than the food.

When a suspect does show up you can see why: how often it was followed by a symptom, how often it was not, how much of it you had, and what else was going on. Days when an antihistamine, your cycle, poor sleep, stress, or a skipped compression garment was doing the work can be set aside in one tap, and the answer worked out again without them.

Your body is nobody else's business.

There is no server to send your log to, because there is no server. This is not a policy that could change with an acquisition; it is the shape of the thing.

Thirty days free, then one payment.

Everything unlocked for a month. After that, one payment — no subscription, no ads, all future updates included. Your history and your export stay readable whether you pay or not.

Thirty days because that is how long it honestly takes. A symptom that lags a week behind a meal needs weeks of days behind it before anything can be said, and a shorter trial would expire before you had seen the thing you would be paying for.