App studio · Heiligenhaus, Germany
MOJM is an app studio. Five apps of our own, each with its own name, its own address and its own point of view. Need one? We’ll build yours too.
Built native. No data for sale. Family-run.
The archipelago
Every app stands on its own: its own name, its own colour, its own domain. What connects them lies below the waterline – the same workshop, the same rules.
Every app is built for its platform. No website in a wrapper.
We don’t sell data, rent out audiences or build advertising profiles.
Live means live, waitlist means waitlist. We name dates once we can keep them.
What an app does and costs lives on its own domain. This is where we tell you why it exists.
Island 01 · Club & coaching software for tennis
Members, courts, fees, league matches and coaching on one platform – with an app for every member included.
Racqt began with the search for a hitting partner and ended up in the club – where the work is spread across spreadsheets, group chats and notice boards. We build it so there’s more time left for tennis.
Island 02 · Mail app for the Mac
Every inbox in one, with calendar and tasks in the same window – and no server of ours in between.
A warft is the raised mound that keeps houses above the tide. We build warfta for the moment the mail starts rising – and so that we never get to see it.
Island 03 · Notebook for Mac, iPad and iPhone
Pages and blocks, databases, daily notes and whiteboards – synced through your iCloud, no account needed.
Notes, plans and lists tend to live in several apps. Tackbook puts them on one page that belongs to you: stored locally, no account, and AI whose tracks you can see.
Island 04 · macOS app for coding agents
Claude Code, Codex, opencode and Gemini CLI keep running when the window’s closed – and the sidebar shows who needs you.
Coding agents work long hours and in packs, and a terminal window is a poor home for that. Cavvy gives them one that keeps running when you close the window.
Island 05 · Side project · audiobooks, music, podcasts
Apps for iPhone, iPad, Mac and CarPlay, and their own server – your media library at home, not in a subscription.
Audiobooks you bought vanish with the subscription, podcasts with the catalogue. Autoreverse is our answer, built in our spare time and open to the community.
Services
What we learn building our own islands goes into your projects: native apps from first sketch to store listing, and AI where it actually takes work off your plate.
Native app development
iOS, iPadOS, macOS and Android, each with the controls that feel right on that platform. With a backend where one’s needed – and without, where it isn’t.
AI consulting
We find the tasks AI can genuinely lighten, test the idea as a prototype and build it into your workflows and apps – with limits agreed up front.
Principles
No investor pressure, no business that depends on data. That leads to a few rules every island follows.
We don’t sell data, rent out audiences or build advertising profiles. Our products pay for themselves.
warfta, Tackbook, Cavvy and Autoreverse work without a server of ours that sees your content: it stays on your device, with your provider or on your own server.
Racqt needs a server, and it’s in Germany. The warfta and Tackbook waitlists run on our own database and mail server, with no newsletter service in between.
Racqt exports everything, Tackbook to Markdown and PDF, warfta to .eml and mbox. If you want to go, your data goes with you.
Software that runs on strangers’ home networks has to be readable. That’s why we’re opening up the Autoreverse server in full.
About MOJM
MOJM is a family-run company from Heiligenhaus in the Mettmann district, just outside Düsseldorf in North Rhine-Westphalia. It started on a tennis court, looking for someone to play with. That became Racqt, our first app – and more islands followed.
No anonymous ticket system, no escalation tiers, no investor pressure: we build software we can stand behind ourselves. Write to us, and the people who build it write back.
Looking for a hitting partner turns into a first idea, and shortly after into a beta.
Racqt launches on iPhone, iPad and Android for tennis clubs, tennis schools and their members.
warfta and Tackbook open their waitlists; Cavvy and the Autoreverse apps are close behind.
FAQ
A family-run app studio from Heiligenhaus, Germany. We build our own apps – Racqt, warfta, Tackbook, Cavvy and the side project Autoreverse – and develop apps and AI solutions for others.
Because each one should stand on its own. What an app does, what it costs and when it launches lives on its own domain. Here on mojm.eu, we tell you why we build it.
Yes. We develop native apps for iOS, iPadOS, macOS and Android, from concept to store, and advise on using AI sensibly. See App development and AI consulting.
That depends on the app. Racqt stores data on servers in Germany. warfta and Tackbook have no server of their own: mail stays with your provider and on your Mac, notes on your device and in your iCloud. Cavvy has no accounts, and with Autoreverse everything lives on your own server.
No. We don’t sell data, rent out audiences or build advertising profiles.
Not across the board. We’re publishing the server of our side project Autoreverse in full – if software runs on your home network, you should be able to read what it does. We’ll name a date once we can keep it.
Yes. Write to us in English or German, and we’ll reply in kind. Some app sites (Racqt, warfta, Tackbook, Autoreverse) are currently German only; Cavvy’s is in English.
Email kontakt@mojm.de or use the form below. We usually reply within 24 hours, and a person does the replying. For Racqt support, write to support@mojm.de.
Contact
A question about one of our apps, a project, or an idea that doesn’t fit any box – your message comes straight to us.