Software company, Valserhône, France
BRT Apps designs and ships mobile apps, web applications and SaaS products. Our software runs on the user's own device wherever it can, and on infrastructure we can account for when it can't.
Whether the product lives in a pocket, a browser tab or behind a login, it gets the same treatment: a small, fast codebase, privacy decided at the architecture level, and a release cadence measured in days.
Native iPhone, Apple Watch and Android products, from first sketch to store listing.
We design and build in Swift and Kotlin, run subscriptions and paywalls, localise into sixteen languages and handle review, release and the long tail of updates. Three of our own products are live today.
Fast, accessible web products that hold up on a phone in a train tunnel.
TypeScript front ends with strict performance budgets, deployed to the edge on Cloudflare. Marketing sites, customer portals and the web half of a mobile product all follow the same rule: ship less, measure more.
Multi-tenant platforms with billing, analytics and AI features that earn their place.
Postgres on Supabase, row-level security from day one, usage-based billing and the Claude API where reasoning over a customer’s own data creates value. Built to be run by a small team without a pager.
We build and operate our own products, which keeps us honest about what shipping actually takes. Each one solves a narrow problem for people who would rather not upload their voice, their medication or their photos to anyone.
Record, trim and transcribe, entirely on your iPhone.
A voice recorder for real conversations. Live captions, speaker-labelled transcripts and summaries run on the device itself: no servers, no bots joining the call, no account.
Next: ask Claude across your own transcripts. Decisions, follow-ups and who promised what, pulled from weeks of meetings in one question.
A private dose log and reconstitution calculator.
For people on GLP-1 and peptide therapy. Every dose, site and vial in one place, with the arithmetic shown on screen and a report you can hand to your doctor.
Next: a Claude assistant that explains your schedule, side-effect notes and bloodwork in plain language, and drafts the questions to bring to your next appointment.
UV forecast, session timer and a private sun journal.
Turns sunny days into one calm routine: hourly UV for your city, sunscreen and flip reminders while your phone stays in the bag, and a before-and-after journal that never leaves the device.
Next: a Claude-powered sun coach that reads your skin type, forecast and plans for the day and writes the routine for you, in your language.
Small teams, strict budgets, and an AI pair that never leaves the room.
Transcription, speaker detection, dose maths and photo journals run on the device. Where a backend is unavoidable, it is Postgres with row-level security, in a region we choose, holding only what the feature needs. Nothing is collected because it might be useful later.
Every product in our catalogue was designed, written, tested and localised with Claude Code in the loop, from Swift and Kotlin to TypeScript and App Store copy. It is how a studio this size ships three products, three Watch apps and an Android port in seven months, and it is how client work gets the same cadence.
Every web surface carries a performance budget. Every mobile release carries crash-free and retention targets. We instrument with PostHog, read the numbers weekly and cut what is not earning its place.
Raw data stays local. What users want to ask of that data is where the Claude API comes in, on exactly the slice they choose to share. Each product has one Claude-powered capability scoped and on the roadmap.
We take on a small number of engagements a year: a mobile app from the first sketch to the store, a web application beside an existing product, or a SaaS platform from MVP to paying customers. Write a few lines about what you are building and we will reply within two working days.
Replies come from the founder, in English, French or Turkish.
BRT Apps is a French software company founded in 2026 by Berkay Turk, an engineer who moved from building products for others to building and operating his own. The company is registered in Valserhône, serves users in sixteen languages, and works with clients across Europe. Partners, press and startup programmes can reach the founder directly.
Write to berkay@brtapps.devRegistry extract
Source: Registre national des entreprises (INPI), SIREN 103051652.
