yukovsky.
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Leaflet

A receipts and warranties app for iPhone and Android. Paper and electronic receipts land in one feed, the app reminds you before a return window or warranty ends, and the archive stays on your phone.

Closed sourcegit clone listokAccess denied: the repository is private.Ask me for a demo
WebsiteTelegram channelIn development, coming to App Store & Google Play

The problem

Paper receipts fade within months, and electronic ones get lost in email or vanish from the self-checkout screen. When a kettle breaks or a jacket has to go back, there is no proof of purchase and nobody remembers the warranty date. Leaflet is for people who buy electronics and appliances, families who share a budget, and anyone who has ever turned the house upside down looking for a receipt.

How it works

You photograph a receipt, scan its QR code or type it in, and it settles into a feed like a pressed leaf in a herbarium, already sorted into a category. Paper receipts are read on the phone itself; the optional cloud step for photos runs on my own server in Minsk. A warranty is a beech leaf that browns as the term runs out; a reminder arrives before the return window or the warranty closes, and the receipt opens full screen for the seller.

What I did

My own product, end to end: the research, the product and its herbarium look, the app for iPhone and Android, and the pitches on stage.

Status

Won a grant at ATOM Startup Day on 4 October 2026. On 16 October I pitched Leaflet at the Student Hub of AI ATOM GLOBAL EXPO, where it was selected from about 140 teams. Next: release on the App Store and Google Play, then the US and EU markets.

Role
Founder and developer
Period
2026 – now
Status
Work in progress
Stack
Flutter, Dart, Riverpod, SQLite, SQLCipher, ONNX Runtime, Node.js, iOS, Android

Key features

  • One feed for every receipt: from a photo of a paper one, by QR code, or typed in by hand
  • Every line recognised, with paper receipts read on the phone itself, and sorted into a category, with search and filters
  • Warranty tracker: the leaf turns brown as the term runs out, with reminders before it ends
  • Return windows tracked too, and a full-screen receipt to show the seller
  • Spending by category, month and store, with CSV, XLSX and PDF export
  • The archive is encrypted on the phone and locked with a PIN or Face ID; a zip backup restores it
Scan a paper receiptSample data

MAPLE HYPERMARKET17.10.2026 18:42

  • Electric kettle 1.7 L39.99Electronics
  • AA batteries ×44.79Household
  • Coffee beans 500 g8.49Groceries
  • Dish soap3.29Household
  • Oat milk 1 L2.49Groceries

TOTAL$59.05

5 items, 3 categories, 1 warranty found

Feed

  • Maple Hypermarket$59.05Today, Electronics, Groceries, Household
  • Green Pharmacy$12.40Oct 15, Health
  • Bean & Leaf Café$6.80Oct 14, Cafés

Spending by month

  1. $342.00Jul
  2. $298.00Aug
  3. $365.00Sep
  4. $273.05Oct

Warranty and return

Electric kettle 1.7 L

Warranty 2 years: 730 days leftReturn 14 days: 14 days left

Illustration of the flow, not a recording. Store, items and prices are made up.
  • Leaflet receipt feed with demo data: cards for Starbucks, Whole Foods Market, Zara and Trader Joe's with dates, amounts, category tags and a return-by dateLeaflet receipt feed with demo data: cards for Starbucks, Whole Foods Market, Zara and Trader Joe's with dates, amounts, category tags and a return-by date

    The feed: every receipt is a card with the store, date, amount and category.

  • Onboarding screen titled Your receipt herbarium: a receipt card from Evroopt with a pressed green leaf, surrounded by small coloured leavesOnboarding screen titled Your receipt herbarium: a receipt card from Evroopt with a pressed green leaf, surrounded by small coloured leaves

    Onboarding: every purchase becomes a pressed specimen in a personal herbarium.

  • A receipt from Zara: date, store address, Return by 3 Dec tag, total $129.00, the store category, Add warranty, a return period with 26 days left and a return reminder switchA receipt from Zara: date, store address, Return by 3 Dec tag, total $129.00, the store category, Add warranty, a return period with 26 days left and a return reminder switch

    One receipt: its category, the return window and a reminder before it closes.

  • Warranties screen with four demo items (headphones, an espresso machine, a laptop and a hammer drill), each with a green leaf, a progress bar and the months leftWarranties screen with four demo items (headphones, an espresso machine, a laptop and a hammer drill), each with a green leaf, a progress bar and the months left

    Warranties: the leaf stays green while the term is fresh and browns as it runs out.

  • Warranty for an espresso machine: valid until 6 January 2028, 425 days remaining, a Documents for the service centre button, brand, model, serial number, seller, service centre and the linked receiptWarranty for an espresso machine: valid until 6 January 2028, 425 days remaining, a Documents for the service centre button, brand, model, serial number, seller, service centre and the linked receipt

    One warranty: time left, product details, the service centre and the linked receipt.

  • Analytics for 3 months: $2,529.79 spent, 3% more than the previous period, a Why more? card, a spending line over the dashed previous period and an average of $17.61 a dayAnalytics for 3 months: $2,529.79 spent, 3% more than the previous period, a Why more? card, a spending line over the dashed previous period and an average of $17.61 a day

    Analytics: how much was spent over a period, how it compares with the last one and why it grew.

  • Onboarding screen titled Warranty is a beech leaf: a notification that a coffee machine warranty ends in 14 days and a row of leaves going from green to brownOnboarding screen titled Warranty is a beech leaf: a notification that a coffee machine warranty ends in 14 days and a row of leaves going from green to brown

    The leaf metaphor: it browns as the warranty runs out, and a reminder arrives in time.

1 / 7 The feed: every receipt is a card with the store, date, amount and category.

The problem

A receipt is the only proof that you bought something, and it is the first thing to go. Thermal paper fades within a few months, receipts get thrown away with the bag, and electronic ones scatter across email, store apps and the self-checkout screen. Then a kettle stops working a year later, and nobody can say where the receipt is or whether the warranty is still running. The 14 days to return a jacket pass quietly too.

Who it’s for

  • People who buy electronics and appliances and want the warranty to actually work for them.
  • Families who keep a shared budget and want to see where the money goes, including the supermarket run.
  • Anyone who has needed a receipt for a return and could not find it.

How it feels

Leaflet is built around a herbarium. Every receipt is a pressed specimen on a card, with the store, the date and the amount written on it like a botanist’s label. A warranty is a beech leaf: green while the term is fresh, brown as it runs out, so the feed tells you what needs attention at a glance. Adding a receipt takes a few seconds: point the camera at it, scan the QR code, or type it in. The app reads the lines and sorts the purchases into categories.

When something has to go back, the receipt opens full screen for the seller. Before the return window or the warranty ends, a reminder comes in time to act. In Russian the app is called Лісток.

What I built

A mobile app for iPhone and Android, in English and Russian, with a light and a dark theme.

  • Four ways to add a receipt: a photo of a paper one, a QR code, a self-checkout flow and manual entry.
  • Text recognition for paper receipts that runs on the phone (ONNX Runtime with Tesseract as a fallback), so a photo does not have to leave it.
  • An import of PDF and HTML e-receipts from a file.
  • A feed with search, filters and automatic categories.
  • A warranty and return tracker with reminders, and a PDF pack of documents for the service centre.
  • A “show to the seller” mode with the receipt full screen.
  • Spending analytics by category, month and store, with CSV, XLSX and PDF export.
  • Privacy by default: the archive is encrypted (SQLCipher), stays on the phone and is locked with a PIN or Face ID. A zip backup restores it on a new phone.
  • My own backend at ai.listok.by on a server in Minsk (Node.js, SQLite): optional cloud recognition of receipt photos through OpenRouter, quotas by plan, and the service behind the Leaflet site at listok.by.
  • An admin in a Telegram bot and Mini App for feedback and for a module of advertising games, with a nightly collector that proposes drafts for me to confirm.
  • Leaflet receipt feed with demo data: cards for Starbucks, Whole Foods Market, Zara and Trader Joe's with dates, amounts, category tags and a return-by dateLeaflet receipt feed with demo data: cards for Starbucks, Whole Foods Market, Zara and Trader Joe's with dates, amounts, category tags and a return-by date

    The feed: every receipt is a card with the store, date, amount and category.

  • Onboarding screen titled Your receipt herbarium: a receipt card from Evroopt with a pressed green leaf, surrounded by small coloured leavesOnboarding screen titled Your receipt herbarium: a receipt card from Evroopt with a pressed green leaf, surrounded by small coloured leaves

    Onboarding: every purchase becomes a pressed specimen in a personal herbarium.

  • A receipt from Zara: date, store address, Return by 3 Dec tag, total $129.00, the store category, Add warranty, a return period with 26 days left and a return reminder switchA receipt from Zara: date, store address, Return by 3 Dec tag, total $129.00, the store category, Add warranty, a return period with 26 days left and a return reminder switch

    One receipt: its category, the return window and a reminder before it closes.

  • Warranties screen with four demo items (headphones, an espresso machine, a laptop and a hammer drill), each with a green leaf, a progress bar and the months leftWarranties screen with four demo items (headphones, an espresso machine, a laptop and a hammer drill), each with a green leaf, a progress bar and the months left

    Warranties: the leaf stays green while the term is fresh and browns as it runs out.

  • Warranty for an espresso machine: valid until 6 January 2028, 425 days remaining, a Documents for the service centre button, brand, model, serial number, seller, service centre and the linked receiptWarranty for an espresso machine: valid until 6 January 2028, 425 days remaining, a Documents for the service centre button, brand, model, serial number, seller, service centre and the linked receipt

    One warranty: time left, product details, the service centre and the linked receipt.

  • Analytics for 3 months: $2,529.79 spent, 3% more than the previous period, a Why more? card, a spending line over the dashed previous period and an average of $17.61 a dayAnalytics for 3 months: $2,529.79 spent, 3% more than the previous period, a Why more? card, a spending line over the dashed previous period and an average of $17.61 a day

    Analytics: how much was spent over a period, how it compares with the last one and why it grew.

  • Onboarding screen titled Warranty is a beech leaf: a notification that a coffee machine warranty ends in 14 days and a row of leaves going from green to brownOnboarding screen titled Warranty is a beech leaf: a notification that a coffee machine warranty ends in 14 days and a row of leaves going from green to brown

    The leaf metaphor: it browns as the warranty runs out, and a reminder arrives in time.

1 / 7 The feed: every receipt is a card with the store, date, amount and category.

Milestones

  • 4 October 2026: grant at ATOM Startup Day, a pitch competition for AI startups in Minsk. I pitched Leaflet to the jury with a bag full of real receipts.
  • 16 October 2026: pitch at AI ATOM GLOBAL EXPO, the AI forum at BelExpo in Minsk. Leaflet was selected for the Student Hub from about 140 teams, and I presented it there with slides on the first day of the forum.

What’s next

  • Release on the App Store and Google Play. Belarus is the first market: the app already works with receipts from local store chains as they are.
  • The US and the EU. Proof of purchase matters there just as much. In the EU, sellers owe a two-year legal guarantee and the buyer has to show where and when the item was bought. In the US, receipts back up health-account claims and the extended warranties that come with many credit cards. I’m researching both markets now.

My role

Founder. I came up with the idea, researched the market, designed the product and the interface, build the app and pitch it myself.

CV.pdf