Suggestions & rhythm

Every check-off is a purchase. From the gaps between purchases of an item, Homecart works out your pace: “milk about every 5 days”. It uses the median of the latest gaps, so one big shop doesn't skew anything, and when your habits change the pace follows within a few purchases.

The rule behind it: rather say nothing than guess. A pace needs three purchases; if the gaps are very irregular, Homecart predicts nothing. Every claim can be checked: long-press a catalog tile to see the proof (“Last bought 6 days ago, you buy milk about every 5 days, 7 purchases”).

Two purchases aren't a rhythm yet, but they are a first gap. Once it has passed, Homecart asks carefully: “Quick question: is it time for milk again?” Such questions are never pre-checked and carry the honest reason “only bought twice”. Answering “Not today” sharpens the pace. The widget and the evening reminder only show what the app knows for sure. The catalog also shows what's still missing: “One more purchase of milk and Homecart knows your rhythm.”

From four shopping trips on, Homecart recognises your weekday if one clearly stands out; two fixed days (say Wednesday and Saturday) are recognised as well. On shopping day the card “Today is your shopping day” sits above the list with everything that's probably missing. The evening before at 7 pm Homecart reminds you, but only if something is actually due. Allow notifications once under Settings → Notifications. What the app has learned is under Settings → About → What the app has learned.

The card opens the sheet “Probably missing”. Clearly due items are pre-checked, borderline ones you tick yourself. What you leave unticked counts as “not now”: Homecart stays quiet for half a cycle, after three times for good, until you buy the item again. This applies to the whole household, whichever device you declined on.

• Too few purchases: under three there's only the careful question, under two nothing.
• Too irregular: if the gaps vary a lot, the app stays silent; the long-press tells you.
• Already on the list: open items count as empty and aren't suggested again.
• Declined: left three times means quiet until the next purchase.
• Deleted instead of checked off: deleted items don't count as purchases.

Add something that was just bought by rhythm and Homecart asks: “Milk was bought 1 day ago, you usually need it every 4 days. Anyway?” No blocking, just a hint with a number. While checking off in the store, a nudge sometimes appears: “You usually also buy: mustard”, for things you mostly get the same day. One tap adds it, the ✕ keeps quiet for today.