Case study

Daiary: turning voice notes into printed books

Daiary lets people speak their stories instead of writing them. The app transcribes voice notes with AI, shapes them into readable text, lays them out as a book, and can have it printed and shipped. As lead Flutter developer I built it from the ground up for iOS and Android, working remotely with the Daiary team in Spain, and it has passed 700K+ downloads.

My role
Lead Flutter developer (Aug 2023 – Jan 2026), project manager (Jan 2024 – Dec 2025)
Platforms
iOS and Android
Stack
Flutter, Dart, Firebase (Auth, Firestore, Cloud Functions), Provider / BLoC, REST APIs
Launched
App Store, February 2024
View on App Store View on Google Play
Daiary recording screen: a large microphone button turns speech into text
Speak instead of typing
Daiary format picker: personal diary, travel diary, story, novel, poetry, news article, essays
Pick a format
Daiary book view: a transcribed diary entry laid out as a book page with a photo
AI lays it out as a book
A printed Daiary travel book held in hand
Order the printed copy

Screenshots from Daiary's App Store listing.

Daiary app icon and preview

The product

Most people have stories worth keeping but never sit down to write them. Daiary removes the writing step: you record voice notes, AI transcribes them into clear, structured text, lays the content out as a book, and with one tap you can order a bookstore-quality printed copy delivered to your door.

It is built for anyone who would rather talk than type: personal and travel diaries, stories with your own characters, essays and reflections, even citizen journalism. The app is free to download on iOS and Android, with in-app purchases.

What I built

  • Architected the app in Flutter with clean architecture, so features could keep shipping without the codebase slowing down
  • Made it offline-first, with Firebase real-time sync keeping users' stories safe across devices
  • Built the push notification system, which increased daily active users by 30%
  • Designed custom UI components and animations that run at a smooth 60 FPS
  • Owned the release pipeline to the App Store and Google Play, plus analytics and crash reporting

Leading delivery

From January 2024 I also managed the project end to end: coordinating a cross-functional team, planning releases across both platforms, and introducing agile practices that cut development cycles by 25%. I worked on monetisation, user growth and store listing optimisation, using analytics and user feedback to decide what to build next.

Results

  • Live on the App Store and Google Play, updated continuously (App Store version 9.1.4, September 2026)
  • Rated 4.6★ on the App Store and 4.2★ from 9,700+ ratings on Google Play (September 2026)
  • 700K+ downloads across iOS and Android
  • 30% more daily active users after the push notification system shipped
  • 25% shorter development cycles
  • €14K+ annual recurring revenue

Building an app that needs this level of polish?

I take on freelance builds, long-term contracts and product partnerships.

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