We know what it takes to make something people genuinely rely on.
fonszi is a software studio that builds products end to end: native cross-platform apps, the systems behind them, hardware and real-time integrations, and AI that actually does something.
Imi
A builder at heart who turned that passion into a company. With 14+ years in software and mobile behind him, including products used by millions, he started fonszi to do great work alongside people he trusts, and to treat every client like one of his own.
Krisz
Krisz builds AI into the heart of every product, turning it from a buzzword into a real edge. He stays on the bleeding edge of the field daily, so what we ship is what actually works now, not last year's hype.
Used by the world's leading companies
What we deliberately avoid
We operate with clear boundaries. These aren't limitations - they're commitments
No outsourcing
Every line of code is written by our core team. We don't delegate engineering to third parties or offshore vendors.
No rushed launches
We won't ship half-baked MVPs to meet arbitrary deadlines. Products leave when they're ready.
No false promises
We tell you what's possible and what isn't. Honest timelines, realistic scope, and transparent communication from day one.
Why We Don't
Our philosophy, in plain language.
A subscription is never the only way in. Every fonszi app can be owned outright - one payment, yours forever, every future update included. No forced renewals, no "trial expired" walls, no meter running while you sleep. If we want your money again, we earn it by shipping something new worth buying.
No sign-up to track your day, no data sold, ever. Our analytics are anonymous and aggregate: we see which features get used, never who used them. The free tier is ad-supported, that's the honest trade for free, and going Pro removes every ad on every screen. This site itself runs on Umami: cookieless, no personal data, no banner to click.
Your ski days and your workouts are yours. They are stored on your device and usable offline, and where you have an account they sync to it so they survive a reinstall and reach your other devices. We run our own backend for the essentials, your account and app updates, and we never hand your data to a third-party broker. You are never locked in: your recorded sessions stay on your phone whatever happens to us.
The server side is ours, end to end. Auth, licensing, the APIs your app talks to: we build and run them, not a rented stack of third-party SaaS. Fewer moving parts, no surprise data-sharing, and one team accountable when something breaks.
iOS (Swift & SwiftUI), Android (Kotlin & Compose), Apple Watch & Wear OS, and high-performance web - all sharing one Kotlin Multiplatform core. We specialize in cross-platform codebases where performance can't be compromised.
Ready to build something?
Let's talk about your next product. Reach out to discuss engineering, strategy, or partnership.