YOU Receipt: Receipt Maker

Inspiration

I love the moment a thermal printer hums and a receipt slides out. A receipt makes an ordinary thing feel official — a tiny transaction becomes a physical record with a total, a barcode, and a "THANK YOU."

So I wondered: what if your day itself got a receipt? Your steps, your sleep, the songs you played — even you.

What it does

YOU Receipt prints your personal data as delightfully real thermal receipts.

13 receipt types: today's you (steps・workouts・heart rate), sleep stages, weather, movement, photos, music, screen time, your device's vitals, a "proof of existence" receipt, and more
A real printing moment: paper feeds out of the printer with haptics tuned to feel like an actual thermal printer — then you pull down to tear it off
Custom receipts: add a title, line items, and one photo (auto background cutout) — perfect for fan-spending (oshi-katsu) or pet expenses, with the TOTAL tallied for you
Collect & trade: torn receipts stack up in a paper archive, and your "member card" receipt can be traded with nearby friends via offline QR — no servers, no accounts
27 languages, pixel fonts included. Health data never leaves the device.

How we built it

iOS: SwiftUI + HealthKit + CoreHaptics. Every receipt is a declarative document model (sections, dashed rules, barcodes, QR) rendered onto simulated thermal paper. The print physics — a 2.6-second paper feed with smoothstep easing, then a damped-pendulum sway after the tear — were tuned by hand until they felt right.
Android: a faithful port in Jetpack Compose + Health Connect + Room, with QR exchange fully cross-compatible with iOS.
Monetization: RevenueCat on both platforms — one premium entitlement unlocks every receipt type, unlimited archive, and watermark-free sharing (lifetime + weekly, no free trial by design).

Challenges we ran into

Making pixels feel physical. The print animation only works if your fingers believe it: haptic transients are synced to the paper feed and a single sharp "tear" impulse. Getting iOS and Android to feel identical took real tuning.
One pixel font, 27 languages. Dot-matrix fonts rarely cover CJK. We audited glyph coverage per language and switch font families at runtime so a receipt in Korean looks as crisp as one in English.
Google Play review, twice. First a missing Health-data disclosure in our privacy policy. Then reviewers found a crash we'd never hit: a localization lookup that threw on one missing key. We reproduced it on the exact release build, replaced the throwing lookup with an iOS-style fallback, audited all 456 keys, and resubmitted. Reviewers turned out to be our best QA.
Trading "yourself" without servers. The exchange format packs a whole profile receipt into a QR payload that both platforms can print — offline, private, instant.

What we learned

A localization lookup must never throw — one missing key shouldn't crash an app in 27 languages.
Privacy is a feature you can print: "your data never leaves the device" fits nicely at the bottom of a receipt.
Emotional framing beats dashboards. The same step count feels completely different when it slides out of a printer with a barcode and a THANK YOU.

What's next

More things deserve receipts — new receipt types, seasonal paper themes, and whatever the community asks for. Tell us: what part of your life should get printed next? 🧾