Quorvel Tide is a small lunar almanac. It computes the moon for any date and time you point it at, draws the phase the way the sky actually shows it, and gives a single approximate number — a tidal coefficient — for how strong the day's tides are likely to swing.
There are four rooms.
Today. The current phase as a moon disc, the percentage illuminated, the moon's age in days since the last new moon, and a card with today's tidal coefficient on a 40–120 scale (Neap → Spring). Underneath, the next New Moon, Full Moon, First Quarter and Last Quarter, in UTC.
Calendar. A month grid where every cell carries its own tiny moon. Tap a day and a detail card opens with the phase name, the illumination percent and the day's tidal coefficient. Step through months with the arrows at the top.
Predict. Pick any future date and time with the system pickers and read the same lunar figures for that moment. There is a latitude slider that gets remembered between sessions, so the tide context lines up with where you actually watch the water. Below the card sits the next four phase events in order.
Quiz. Ten rounds. A moon disc is drawn at one of eight canonical phases; pick the name from four options. A short vibration confirms each tap, the best score is kept across sessions, and a new round can be started at any time.
The moon disc is drawn from scratch on a Compose canvas — a dark disc, a lit hemisphere, and a terminator ellipse whose width follows the cosine of the phase angle. The tidal coefficient is a synodic-anomalistic mix, not a NOAA reading, and it is labelled as approximate in the app itself.
Quorvel Tide keeps everything on the phone. The latitude and the quiz best score live in a local DataStore file. There is no account, no sync, no internet permission in the manifest, and no analytics. The only permission held is VIBRATE, used for the quiz feedback cue.