Case study · 08/10
Cachet
Invoices, quotes and receipts — offline, with country-aware taxes.
- Category
- Mobile apps
- Year
- 2026
- Status
- Google Play · closed testing
- Languages
- EN · FR · AR · DE · ES · IT · PT
01
Overview
An invoicing app for freelancers and small businesses: quote, invoice, get paid and issue a receipt from the phone, with tax presets per country and PDF templates.
02
Our solution
A Flutter app where money is stored in integer minor units, never floating point, and every tax and numbering rule is unit-tested. Presets were checked against official tax sources.
03
Key features
- 01
Quote → invoice → receipt flow
- 02
Country tax presets
- 03
PDF templates and sharing
- 04
Client signature on quotes
- 05
Payment reminders
- 06
Voice entry and document scanning
04
Engineering highlights
- 01Integer money arithmetic
- 02729 automated tests
- 03Seven interface languages including Arabic (RTL)
05
Technology
- Flutter
- Dart
- Riverpod
- drift
- ML Kit
- Play Billing
06
Screens
Scroll sideways or use the arrow keys to see every screen.
07
Availability
In closed testing on Google Play — public release coming soon.
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