# LenkoLab

> LenkoLab is a two-person software studio based in Coimbra, Portugal (EU). We build business software to order - mobile apps, web platforms and SaaS - and develop our own product line in the same domains: invoicing, document scanning, inventory, field service, and accounting tools. Fixed scope, fixed price, no hourly billing.

## What We Do

- Custom mobile app development: from a written spec and concept to store release, with support after launch. Offline-first is our specialty.
- Custom web and SaaS development: niche SaaS tools, online calculators and quoting tools, custom CRMs and internal tools, B2B ordering portals, migration from spreadsheets to web systems.
- Paid extensions of our free apps: multi-user versions, cloud sync, dashboards, and integrations built to order on top of any app below.
- We do not offer marketing, promotion, or SEO services.
- We do not bill by the hour: a fixed price for a fixed scope, agreed before work starts. A focused app typically takes 2-4 months from spec to release.

## Mobile Apps (our own products)

- [Fyntoo Bill](https://lenkolab.com/mobile-apps/fyntoo-bill.html): free offline invoicing app for freelancers and small businesses. PDF invoices with your logo, per-client invoice language, payment tracking. Data never leaves the device. Live.
- [Fyntoo Scan](https://lenkolab.com/mobile-apps/fyntoo-scan.html): free offline document and receipt scanner. Edge detection, multi-language OCR, expense categories, CSV/PDF reports. All processing on device. Live.
- [Yarna](https://lenkolab.com/mobile-apps/yarna.html): voice-first mobile CRM for independent real estate agents. Dictate after a viewing and the client card fills itself in; promises with due dates, morning brief, offline dictation. Paid subscription with a 30-day free trial. In beta, preparing store release.
- [Fyntoo Field](https://lenkolab.com/mobile-apps/fyntoo-field.html): free field-service app for solo tradespeople and micro-crews. Work orders on a map, geo check-in, result photos, client signature as proof of visit. In testing.
- [InvoStock](https://lenkolab.com/mobile-apps/invostock.html): free offline inventory app with barcode scanning, stock movements, low-stock thresholds, CSV export. In testing.

## Web & SaaS (our own products)

- [FX Diff](https://fxdiff.pl): SaaS that calculates FIFO foreign-exchange rate differences required by Polish accounting regulations (NBP rates, PDF documents for the ledger). For Polish sole traders (JDG) and accounting offices. Affordable subscription with a free tier and a 14-day trial. Live at fxdiff.pl; details at https://lenkolab.com/web-projects/fxdiff.html.

## Track Record

- 25+ years of web and mobile engineering behind the studio; most client work is under NDA.
- Public client work for Printstore Group: online printing calculators with order placement, a CRM for managing customer orders, and the Paperstore paper-ordering service. The director's recommendation is published on https://lenkolab.com/.
- Systems delivered more than a decade ago are still in daily use.

## Blog (practical guides, written from experience)

- [How much does a custom mobile app cost? An honest breakdown](https://lenkolab.com/blog/custom-app-cost.html)
- [How to write a spec for your app (a one-page template)](https://lenkolab.com/blog/how-to-write-an-app-spec.html)
- [When you do not need a custom app](https://lenkolab.com/blog/when-you-do-not-need-a-custom-app.html)
- [Five signs your inventory has outgrown the spreadsheet](https://lenkolab.com/blog/spreadsheet-inventory-five-signs.html)
- [Proof of visit: how solo tradespeople win disputes](https://lenkolab.com/blog/proof-of-visit.html)

## Key Pages

- [Mobile apps and what we build to order](https://lenkolab.com/mobile-apps)
- [Web & SaaS and what we build for clients](https://lenkolab.com/web-projects)
- [Custom development: process, domains, engagement models](https://lenkolab.com/custom)
- [About the studio](https://lenkolab.com/about)
- [Blog index](https://lenkolab.com/blog/)
- [FAQ on the home page: cost, timeline, post-launch support](https://lenkolab.com/)

## Contact

- Email: hello@lenkolab.com
- Form: https://lenkolab.com/contact (reply within 2 working days)
- Location: Coimbra, Portugal, EU
- Languages: English, Portuguese, Polish, Ukrainian
- Founder: Nadiia Linyvenko