Kosu Apps
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✦ Independent app studio · est. 2025

Apps crafted with care, for everyday life.

Kosu Apps is a small, independent studio making considered mobile apps and games — privacy-first, beautifully designed, with select apps available in 30+ languages.

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iOS & Android 30+ languages Privacy-first
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Step 3 of 12
Shoulders
Breathe in slowly… and gently lift your shoulders toward your ears.
›
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Car Care Scheduler
My cars
Corolla
Oil change
9 days
Mazda MX-5
Inspection
3 wks
VW Van
Brake pads
On track
＋ Add car
Volleyball Hero menu over a live indoor volleyball arena
Our apps

Three apps. One obsession with the details.

Different problems, same philosophy: do one thing genuinely well, keep it private, and make it a pleasure to use.

🚗 Vehicle maintenance

Car Care Notifier

Never miss a service again.

Track every car in one tidy garage. Log oil changes, inspections and custom services, then let smart reminders nudge you two weeks before anything is due.

  • Multi-car garage with per-car reminders
  • Odometer & date tracking, km or miles
  • Works offline — your data stays on device
Explore Car Care →
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Car Care Scheduler
My cars
Corolla
Oil change
9 days
VW Up!
Inspection
3 wks
＋ Add car
🌙 Sleep & relaxation

Pillowy

A gentle wind-down for restless nights.

A friendly pillow guides you through a self-paced muscle-relaxation routine — breathing along with you while a glowing body map travels calmly from neck to toes.

  • 12 guided steps, entirely at your pace
  • Personalized by name, struggle & body
  • Night-streak tracking to build the habit
Explore Pillowy →
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Step 5 of 12
Hands & arms
Let go, and feel the warmth spread through your fingers.
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🏐 Mobile sports game

Volleyball Hero

Swipe. Set. Spike. Build your legacy.

Master every touch in a swipe-controlled 3D volleyball game. Receive, set, serve, block and spike through quick matches, international competition and a multi-season club Career.

  • Gesture-based ball direction, power, arc & curve
  • Career, League of Nations, Quick Match & training
  • Offline and private, with no accounts or tracking
Explore Volleyball Hero →
A player draws a pass toward the setter in Volleyball Hero
Why Kosu

Built the way good apps should be.

No accounts to create, no data to harvest, no dark patterns. Just careful software that respects your time and your privacy.

Privacy by default

Your information lives on your device — not our servers. No sign-ups, no tracking, nothing sold. Ever.

Designed to delight

Soft motion, honest color, and details that feel just right. Every screen earns its place.

Speaks your language

Car Care Notifier and Pillowy are localized in 30+ languages, with units and wording tuned to each region — not machine-dumped.

Built for mobile

Every product starts with the phone in your hand. Our utility apps span iOS and Android; Volleyball Hero currently targets Android.

Quietly powerful

Smart reminders, gentle guidance and expressive touch controls — useful depth without needless friction.

Made by a human

A one-person studio that reads every review, fixes the small things, and ships with intention.

3
Thoughtful apps
30+
Languages supported
100%
On-device privacy
0
Ads & trackers
Global by design

Select apps, at home in dozens of languages.

Localization varies by app. Volleyball Hero is currently in English while it is in development.

EnglishPolskiDeutschEspañolFrançaisItalianoPortuguêsNederlandsУкраїнськаČeštinaSvenskaSuomiDanskNorsk日本語中文हिन्दीالعربيةTürkçeΕλληνικάMagyarRomână EnglishPolskiDeutschEspañolFrançaisItalianoPortuguêsNederlandsУкраїнськаČeštinaSvenskaSuomiDanskNorsk日本語中文हिन्दीالعربيةTürkçeΕλληνικάMagyarRomână
The studio

Small studio. Big care for the small stuff.

Kosu Apps is the work of one independent developer who believes the little apps we reach for every day — the ones that remind us, calm us, challenge us, and quietly help — deserve the same craft as the big ones. No venture funding, no growth-hacking, no compromise on privacy. Just focused, useful apps, made and maintained with care, whether an everyday utility or a game.

Say hello See the apps
Get in touch

Have an idea, a bug, or just want to say hi?

Feedback shapes everything Kosu makes. Reach out any time — every message is read by an actual person.

✉ szymon.kosu@gmail.com