Products
21 products across the web and Android. Each one is free to start, quick to open and built to keep your work on your device.
Platform · ls-judge
ls-judge is our self-hosted online judge and code-execution API. Every submission runs inside its own Firecracker microVM with an isolated network namespace, and per-test verdicts stream back live over WebSocket.
Products
Scheduler
ls-judge
HTTP API · WebSocket · webhooks
Hot lane
Warm snapshot pool · milliseconds
Cold lane
Snapshot restore on demand
Queue
Redis streams · stateless workers
Results stream back over WebSocket
Firecracker microVMs
Each submission boots in its own Firecracker microVM with a private network namespace, seccomp and a jailer — never a shared container.
Warm snapshot pools serve popular languages in milliseconds; everything else restores from a cold snapshot on demand.
Verdicts, run time and memory for every test case stream back over WebSocket as they finish — no polling.
01 · Developer tools
Editors, compilers and utilities that open instantly and keep your work on your device.
Run untrusted code in 65+ languages, each in its own microVM.
Our code-execution platform and API. Every submission is isolated in a Firecracker microVM, with per-test verdicts streamed live. It powers Omni Compiler and the Online Code Editor's Run button.
A multi-file IDE that opens in a browser tab.
Write in 80+ languages on the same engine that powers VS Code. Preview Markdown, diff files, test APIs and run snippets — with your files kept on your device, not our servers.
A LaTeX editor that compiles offline, on your phone.
Write LaTeX and compile it to PDF on the device with a real XeTeX engine. Live preview, templates, Git and Google Drive sync, and Snap math that turns handwriting into LaTeX — no account needed.
A Typst editor with a live preview, on your phone.
Write Typst and watch the PDF update as you type. The Typst compiler runs on the device, with Typst Universe packages, templates, LaTeX import and Snap math for handwritten formulas.
35+ CSS generators with live preview.
Gradients, shadows, glassmorphism, animations, flexbox and grid builders, colour converters and accessibility checks — each with instant preview and one-click copy.
Open and search huge JSON files on your phone.
A fast JSON viewer with an interactive tree, streaming search and file management — tuned for large, deeply nested documents.
Convert images to Base64 in bulk.
Drop any number of images and copy Base64 output instantly. Conversion happens in your browser — nothing is uploaded.
02 · Create & share
Turn scripts, drawings, vectors and conversations into something worth sharing.
Edit SVG visually and in code — at the same time.
A multi-file vector editor with node-level path editing and live two-way SVG code. Every change on the canvas updates the markup, and every markup edit flows back to the artwork.
A teleprompter that keeps pace with your voice.
Write or import a script and read hands-free. Voice tracking scrolls with how you actually speak, across languages, with camera recording and on-device storage built in.
Turn WhatsApp chats into print-ready memory books.
Import an exported conversation and get a beautifully typeset PDF with photos, themes and keepsake stats. Parsing and rendering happen entirely in the browser — nothing is uploaded.
03 · Learning
Hands-on ways to practise code, visualise algorithms and build early literacy.
Compile and judge code in 61 languages.
Run code against test cases on your phone with real verdicts — accepted, wrong answer, time limit and more. Every run executes on ls-judge in its own isolated microVM, across 114 language runtimes.
Draw over any screen while you teach or present.
A free drawing overlay for tutorials, live sessions and quick annotations — multi-colour brushes, undo and redo, opacity control and shake-to-draw.
Watch algorithms and data structures work, step by step.
Interactive simulations of sorting, trees, graphs and more — built for students, teachers and interview preparation.
Handwriting practice A–Z with gentle AI feedback.
Children trace and write letters on a digital whiteboard and get encouraging, recognition-based feedback — a playful, no-pressure path to early literacy.
Scriptures and mantras to read, listen to and share.
Classic Indian texts in a modern reader with audio and text modes, so traditional wisdom is easy to explore every day.
04 · Everyday & privacy
Small, focused apps for planning, automation, documents and private messaging.
Merge, split, compress and scan PDFs.
An all-in-one PDF toolkit on Android and the web: merge, split, compress, convert and scan documents with on-device text recognition.
Turn gestures and device events into actions.
Shake to screenshot, flip face-down for Do Not Disturb, tap a floating button to lock — a visual workflow builder that runs entirely on-device with no account.
A calm task planner where nothing silently disappears.
Overdue work rolls into a gentle review instead of vanishing. Exact-time reminders, recurrence and a home-screen widget that stays in sync.
Anonymous messages only you can read.
Share a link and receive end-to-end encrypted anonymous messages. The server stores ciphertext only, and your private key never leaves the device keystore.
Easier on the eyes after dark.
A configurable screen overlay that reduces glare and strain at night, with quick toggles and a home-screen widget.
Open source
Reusable pieces extracted from our products and published for anyone to use.
@vi5hnuu/ngx-scribblyAngular directive to draw, resize and place components or templates directly onto any container.Angularngx-smart-scrollDirection-aware infinite scroll with precise thresholds, throttling and one-time position triggers.Angular@vi5hnuu/ngx-notiLightweight notification system with stacking, template support and Shadow DOM encapsulation.Angular@vi5hnuu/ngx-movementUtilities for moving and animating DOM elements in Angular applications.Angularls-notiStacked snackbar system for Jetpack Compose with queueing and custom layouts.Jetpack ComposeGoogle Play
All 16 Android apps, one developer page.
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