Mori Period App Recomputes Predictions Instead of Storing Them

The developer of Mori, an offline period tracker with no account, explains why the app does not save its predicted dates in a database. Stored predictions go stale when past entries are corrected, can create mismatches between screens, and add extra data that must be deleted. Instead, the app stores only the dates users mark and recalculates predictions from that history using an explicit as-of date. The developer notes this makes results reproducible and simplifies deletion, at the cost of recomputing on each read. The phone is the only copy of user data by default, so keeping a single source of truth is treated as important.