CaloriBank(カロリ貯金)

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  CaloriBank app icon — Omochi the piggy bank (1024×1024, uncropped).

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  Home: Omochi lives on a tatami mat. Log a win in 3 seconds with the Record button.

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  Omochi's room grows as you save — 165 gift items, monthly seasonal editions, and a garden view.

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  Premium AI estimate: "a regular beef bowl instead of large" → +200 kcal saved. $0.99/mo via RevenueCat.

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  Interactive widget plus weight, blood pressure, and drink counts — logged without judgement.

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  Monthly report with savings and streaks — designed for real occupational-health counseling.

Inspiration

Most diet apps are guilt trackers: they count what you ate and show you what you did wrong. CaloriBank (カロリ貯金 — "calorie savings") flips the model. It only records what you did: choosing a regular beef bowl instead of large (+200 kcal saved), skipping one beer (+140), walking 30 minutes (+80). Savings become coins, and coins become gifts for Omochi, the piggy-bank pig who lives in a little tatami room on your phone.

No calorie budgets. No red numbers. No judgement.

What it does

• Additive-only tracking — you can't fail, you can only save
• 3-second logging with presets or manual entry
• AI calorie estimates and comparisons (Premium) — estimate calories saved from a skipped item or extra activity, or compare two foods or drinks to see the difference and gradually build an intuition for choosing without looking up every calorie
• Omochi's room — spend coins on 165 gift items; a limited-edition seasonal gift arrives every month (Setsubun beans, cherry blossoms, summer-festival lanterns...)
• Drink Counter — tap-to-count drinks from an interactive Home Screen / Lock Screen widget (iOS 17 AppIntents), reviewed in the calendar with pure-alcohol totals. Counting, not scoring — treated exactly like weight and blood-pressure notes
• Weekly / monthly reports & CSV export designed so an occupational health nurse can actually use them in counseling sessions

The story we're most proud of

An occupational health nurse colleague reviewed the app for use in health guidance and asked for one thing: a dead-simple drink counter. We designed and shipped it in one day — in-app counter, interactive widgets, calendar integration — and field-tested it the very next evening at a work dinner with occupational-health professionals. The first user feedback after launch (long-press to edit presets, a weekly chart view) shipped within 24 hours.

How we built it

Flutter + Riverpod + Drift (local-first: your health data stays on your device), Swift WidgetKit + AppIntents for the interactive widgets sharing data via App Group, a Cloudflare Workers proxy for AI calorie estimation (API keys never ship inside the app), and RevenueCat for the gentle premium tier.

Challenges we ran into

Designing "positive-only" mechanics that stay honest: streak bonuses that don't punish breaks, a drink counter that never scolds, and a savings cap so that skipping drinks can't be gamed into absurd numbers.

Latest update: Android launch

CaloriBank is now live on both iPhone and Android. After the iOS launch, I completed Google Play's testing and production review process and shipped the same core experience on Android.

The Android release also exposed a distribution gap: the website, video description, and Shipaton submission still pointed only to the App Store. I updated those paths so Android visitors now reach the correct store.

What's next

HealthKit steps with a rolling 90-day personal baseline (your own bar — it rises gently, not like a sports watch), a professional mode where a health nurse enters your usual weekly alcohol units after a counseling interview, and an Apple Watch complication for the drink counter.

Built With

• app-intents
• cloudflare-workers
• dart
• drift
• flutter
• openai
• revenuecat
• riverpod
• swift
• widgetkit