Est. 2026 · Helsinki

Limecore

A personal OS suite, built in high school.

Three apps that sync to each other over Realtime. Local-first. Open source. Helsinki.

GitHub ↗
01 /

Projects

001
Nexus Command Center

A local-first life dashboard. Finance, studies, fitness, and tasks — synchronised across your devices, powered by your own API keys.

The hub of the suite. Reads workouts from LimeLog and study hours from StudyDesk over Supabase Realtime, plus its own finance, tasks, and goals modules. Dexie + IndexedDB local-first, BYO API keys, biometric unlock, cross-module weekly reviews that single-purpose apps can't surface.

React TypeScript Capacitor Dexie Supabase Tailwind Zustand
Local-first
GitHub ↗
Nexus Home screen
Home
Nexus Goals screen
Goals
Nexus portfolio screen
Portfolio
Nexus weekly review screen
Weekly Review
Nexus what-if simulator screen
What-If
LimeLog Lock In mode
Lock in
LimeLog phases view
Phases
002
LimeLog

Periodized workout tracker built for competitive athletes. Log sets, track vertical jump, manage injury restrictions, and get phase-aware progression insights. Writes into Nexus Fitness over Realtime.

React TypeScript Vite Zustand Capacitor
In progress
GitHub ↗
StudyDesk grades view
Grades
StudyDesk Pomodoro logger
Pomodoro
003
StudyDesk

Study planner for IB (1–7) and US (4.0) grading. Course list, Pomodoro logger, session journal. Writes into Nexus Studies over Realtime — what you log here surfaces in the hub.

React Capacitor Supabase Android
Local-first
GitHub ↗ F-Droid ↗
// Side experiments
x01
Krata

Project-scoped AI command center. Bloomberg terminal for thinking. Structured, fast, no bloat.

Paused
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The Suite

Three apps, one data graph.

LimeLog logs your set. StudyDesk logs your Pomodoro. Both write into the same Supabase project. Nexus Command Center reads — workouts surface in Fitness, study hours surface in Studies, weekly reviews pull from both. Cross-app updates land in ~1.5 seconds via Realtime, last-write-wins, offline outbox queued.

Local-first via Dexie / IndexedDB. Cloud sync over Supabase. End-to-end identity with email/password or Google OAuth. Biometric unlock and PBKDF2-SHA256 PIN with tiered brute-force lockouts on the hub.

No third-party data brokers. No subscription. Bring your own API keys for market data. The whole stack costs zero per user beyond what you choose to pay your providers.

LimeLog WRITER StudyDesk WRITER Supabase REALTIME · ~1.5s Nexus HUB · READER
// last-write-wins · offline outbox · ~1.5s p50 latency
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How I build

AI-in-the-loop
Local-first
TypeScript
Real device, not just emulator

Limecore ships fast because most of it is built with AI in the loop. Claude and Cursor write a serious share of the code; my job is architecture, taste, and the boring 20% that decides whether a thing is actually shippable.

Local-first by default, because cloud-first SaaS is what these apps are reactions against. TypeScript everywhere. Tested on a real Android device, not just emulators. Every release on every app goes through the same security checklist: CSP, secret-detection pre-commit, AndroidManifest hardening, source maps off in production.

Build logs and architecture writeups coming soon.

Blog ↗build logs & writeups
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About

HEL
Helsinki, Finland
4
Projects in flight

Limecore is a one-person studio based in Helsinki, run by a high-school student learning to ship real software in production. Tools that don't exist yet — life dashboards, training systems, study apps, AI infrastructure.

Local-first by default. Secure at rest. Designed for one person at a time, architected for more. Built because the existing options are too slow, too bloated, or too generic — and to learn what real shipping actually takes. Everything ships under Limecore.

Android Local-first Open source Life dashboards AI/LLM Fitness