R&D mechanical engineer with an aerospace background: product reliability, DVT, NPI and root-cause analysis.
On the side I build offline-first tools and AI experiments, and I'm learning Fortran for CFD work.
Portfolio Β· LinkedIn Β· Email Β· Featured Β· Building Β· Tools Β· Games Β· Engineering Β· β¨ All projects as landing pages
|
Local-first No account, no server required. Most of what I ship keeps working offline. |
Real apps on every platform Desktop installers, Android and iPhone builds, and a live web demo you can try right now. |
Built like hardware Test suites, versioned releases and an engineer's habit of verifying before shipping. |
Ranked by how solid each project is: test suites, shipped releases and downloads, a working live demo and commit history. Click any card to open it.
![]() Airiz Motor: USB jog, remote control and camera by code, live device checks and a camera-based wobble test. βΆ Try it live Β· β¬ Download Β· β¨ Landing page Β· π README |
![]() Twin: Invest and day-trade with a twin that replays 10,000 futures before you risk real money. βΆ Try it live Β· β¬ Download Β· β¨ Landing page Β· π README |
![]() Glow: Four AI apps on one free account, in 4 languages. No API keys, and it keeps working offline. βΆ Try it live Β· β¬ Download Β· β¨ Landing page Β· π README |
![]() Buddy: Hold Ctrl+Alt+Space, ask about anything on screen, and it answers out loud and points at it. Free brain out of the box. β¬ Download Β· β¨ Landing page Β· π README |
![]() Datum Bench: NPI task flow, review checklists, an issue log and 11 engineering calculators in one place. βΆ Try it live Β· β¬ Download Β· β¨ Landing page Β· π README |
![]() Mint: Synced on every device, with expenses you log by texting Mint on WhatsApp. βΆ Try it live Β· β¬ Download Β· β¨ Landing page Β· π README |
![]() Vitals: Cleans storage you can undo, forecasts battery wear and finds what drains your device. βΆ Try it live Β· β¬ Download Β· β¨ Landing page Β· π README |
![]() EarlyStar: Find GitHub repos before they trend, ranked by the stars they actually gained, with real activity next to the hype. βΆ Try it live Β· β¬ Download Β· β¨ Landing page Β· π README |
30 projects in progress, ranked by how solid they are, then potential
Ranked by how solid each project is (tests, releases, a working demo), then by potential. Activity refreshes automatically every 2 hours.
- Sync
: Listen to music together in real time from anywhere, with Spotify, Apple Music, YouTube and shared files in one room, plus voice chat that lowers the music.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 2 commits this week Β· latest: License: MIT everywhere: README License section, license = MIT in 15 paβ¦ - Guang Yao Together ε
θεθ‘
: An unofficial Traditional Chinese learning app with admin-published lessons, an AI study companion, spaced review and streaks. A PWA, an Android app and a free iPhone home-screen app.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 2 commits this week Β· latest: License: MIT everywhere: README License section, license = MIT in 15 paβ¦ - Peers
: Verified reviews across category modes (food, travel, market, AI tools, health, finance). Every category shares one interface, with a built-in Use it / Wait / Skip scorecard.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 2 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - Atomize
: AI content repurposing SaaS. Paste one blog post, get 5 LinkedIn posts, 8 tweets, 3 newsletters and a YouTube Short script. Next.js 14 + Claude, Lemon Squeezy for payments.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 3 commits this week Β· latest: License: MIT everywhere: MIT LICENSE (Juwen Lie), README License sectioβ¦ - Haru
: A cozy photo diary, walking map and weather town in a Japanese/Korean indie style. Each day is a card with a tiny diorama lit by that day's weather, a photo, a note and the streets you walked, plus a screenshot tidy-up with on-device OCR. English, Japanese, Korean or both side by side. Runs in any browser; Android, Windows and Mac downloads.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 5 commits this week Β· latest: License: MIT everywhere: README License section, license = MIT in 15 paβ¦ - Lingua
: Floats a translated-caption window over Microsoft Teams. It screen-reads the live-caption strip, OCRs it and translates as the speaker talks, so a mixed-language meeting lands on your screen in your own language.
β¨ Landing page Β· π README Β· π‘ Updated Oct 28 Β· quiet this week Β· latest: lingua: install & usage guide deck, share kit (guide builder + Outlookβ¦ - Fade
: A barber marketplace and short-video app in one. Find a barber from a 15-second cut, book their slot at whichever shop they work in that day, pay them directly and tip; the creator of the short that sent the booking earns a commission. Multi-user and online with no server and no fees (Nostr relays), and Fade takes 0%.
β¨ Landing page Β· π README Β· π‘ Updated Oct 30 Β· 1 commit this week Β· latest: Fade for Windows: the live Fade app in its own window - Sweep
: The
/sweeppipeline: validate an idea, then sync the repo to GitHub and mirror a note to Obsidian. PowerShell helper plus an OpenCode slash command.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 4 commits this week Β· latest: License: MIT everywhere: README License section, license = MIT in 15 paβ¦ - Nudge
: Friends send you reels, you doomscroll past them. Nudge reads your own Instagram, WhatsApp, Telegram and iMessage exports and shows who you've been leaving on read, which shares you never answered, and a ready-to-send opener to reconnect. Weekly digest, iOS widget, Python CLI, 100% local.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 11 commits this week Β· latest: License: MIT everywhere: MIT LICENSE (Juwen Lie), README License section - Hazel
: One creator studio, three apps: Hazel Shorts for faceless explainer shorts, Hazel Sped for sped-up and mashup edits of your songs, and Hazel Long to create, cut and publish long-form video.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 4 commits this week Β· latest: License: MIT everywhere: README License section, license = MIT in 15 paβ¦ - Pips
: Desktop pet and Pomodoro widget for Windows: 51 animals that walk, swim and fly, friends and chat, turn-based skill battles, minigames, live weather and 4 languages. Includes Focus Trail and Phone Trail.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 30 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - Orbis
: Communication, identity and protection in one app, plus Orbis Chat: real-time messaging with accounts, teams, email invites and push notifications on web, iPhone and Android.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 3 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - House of Articles
: Athlete-moment sneaker news plus a live market feed, linking on-court moments to resale price moves.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 1 commit this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - Undanu
: Digital wedding invitations for Indonesia with RSVP and a guest book. Couples design an envelope-style invitation with a live phone preview, send each guest a personal link on WhatsApp, see who opened it and who's coming, send reminders, collect wishes, song requests and gift or charity confirmations, and check guests in with a QR e-pass on the day. Templates for every religion in Indonesia (incl. Konghucu and Kepercayaan), video covers and motion-photo galleries, a LIVE badge for streamed ceremonies, Instagram Story sharing, Bahasa Indonesia / English, zero-dependency Python and SQLite.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 19 commits this week Β· latest: License: MIT everywhere: README License section - Jeda
: A quiet virtual space and living library for every faith in Indonesia (Islam, Protestant, Catholic, Hindu, Buddhist, Confucian and Chinese-Indonesian temple traditions), inspired by Korea's Sansa. Light incense or a candle in your own space, visit others' spaces respectfully, read teachings and rituals per stream and dialect, plan ceremonies, track holy days (Imlek, Hijri, Pawukon), and keep family memorial dates and traditions. Content is reviewed in the open by verified clergy, no account, works offline. Bahasa Indonesia.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 20 commits this week Β· latest: v1.5.0: first-person view, day/night switch, sacred objects in hand (maβ¦ - Push Lab
: Two tools for mobile QA: Beacon is a self-hosted push server, and Tether puts your Android phone in the browser with scripted QA flows.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 8 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - The Morning Paper
: A morning newspaper for markets, AI and chips, robotics, space and tech. It scans hundreds of headlines, merges stories covered by several outlets, adds an AI brief and a "why it matters" line, and keeps a stock desk with valuation scores and live prices. Sign in once and your portfolio and price alerts follow you to every device; a Windows Stock Desk app syncs the same data.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 22 commits this week Β· latest: edition 2026-11-04 20:04
- Steward
: A drop-in governance layer that keeps embedded AI on-mission. It detects off-task use, deflects curious drift, blocks hostile prompt injection and attributes cost, with an audit log and a Next.js dashboard. Python and TypeScript SDKs plus an OpenAI-compatible proxy.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 4 commits this week Β· latest: License: MIT everywhere: README License section, license = MIT in 4 pacβ¦ - Rewind
: A community archive for old TV series that are hard to find on today's streaming platforms. Share memories and quotes, keep a personal shelf and track where a show can still be watched. Runs in any browser and installs on phones.
β¨ Landing page Β· π README Β· π‘ Updated Nov 2 Β· 1 commit this week Β· latest: rewind: add Rewind (community archive for old TV series missing from stβ¦ - ScopeGuard
: Keeps a business AI assistant on its mission: allows on-topic requests, steers related ones back, redirects off-topic use without calling the LLM and blocks jailbreaks. Dashboard shows LLM cost avoided and what users really want; runs in the browser, with a self-hosted Python server for production.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 2 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - Teman Sehat
: GERD and acne lifestyle companion in English and Bahasa Indonesia: daily reminders, an after-meal timer, a symptom and trigger log, diet and fitness without fasting, and acne care with a skin routine.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 3 commits this week Β· latest: License: MIT everywhere: README License section, license = MIT in 15 paβ¦ - Sortie
: A file organizer that's fun to use: sorted files fly into their folders and a vacuum cleaner sucks up deletes into a recoverable bag. Ask the AI assistant in plain words and it shows a plan you Run or Cancel. Everything is undoable.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 2 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - E-coder
: A stdlib-only coding agent that reads a repo with gitignore-aware tools, plans, edits files and runs commands behind a deny-list and fail-closed confirmation. Default model is local Ollama, no API keys. 67 hermetic tests, zero third-party deps.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 6 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - CrewCup
: Office coffee for teams in Indonesia and Southeast Asia: order your usual in one tap or join a group coffee run, pay from the company allowance and pick up at partner cafΓ©s with your company badge. Includes a cafΓ© order board, HR budgets and audit log, company rewards, points, tiers and coupons, and a network to meet other companies in your building. EN / ID, plain Python and SQLite.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 2 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - shiphub
: Pinterest for app ideas, with forum threads: save ideas to boards, discuss them, fork them, claim one with "I'm building this" and mark it shipped with repo and demo links. GitHub sign-in, plain Python with SQLite or Postgres.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 10 commits this week Β· latest: License: MIT everywhere: README License section - LaunchKit
: Promote your app before it's finished. A waitlist where every friend you invite moves you up the line, confirmation and reward emails, an AI social media manager for build-in-public posts, tracked links that show which post brought each signup, and a launch-week plan with Product Hunt and Show HN checklists. Clean dashboard with a sidebar, dark mode and a phone-friendly layout; opens as a desktop app. Zero-dependency Python and SQLite.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 7 commits this week Β· latest: License: MIT everywhere: README License section - Signals
: Free, $0-capital crypto signal bot: RSI + MACD + ATR + EMA confluence alerts on 4h candles, paper-trades every signal and ships with a backtester, a robustness sweep and a risk-capped Binance executor. One Python dependency.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 4 commits this week Β· latest: License: MIT everywhere: README License section - SkillMouse
: Use your Claude Code, Codex and OpenCode skills and agents with any model, straight from the mouse. Select text anywhere, press the side button (or Ctrl+Shift+Space, or Ctrl+drag for a radial donut) and run a skill or agent on it with a local Ollama model or any OpenAI-compatible endpoint. Finds SKILL.md, agents and commands from Claude, Codex, OpenCode and Gemini folders automatically; Raycast-style launcher with favourites, a Ctrl+K actions panel, streaming markdown results and 7 themes. Windows, single-file Python. Ships with
refine-loop, an improve-until-done skill: frozen rubric, baseline score, separate judge, keep-best and hard stop rules.
β¨ Landing page Β· π README Β· π’ Updated Nov 4 Β· 3 commits this week Β· latest: examples: add refine-loop skill (improve-until-done with frozen rubric,β¦ - Titian
: A broker-run B2B bridge for industrial manufacturers in Southeast Asia: each company gets a showcase with an interactive 3D catalog, RFQ basket and supplier portal, with every introduction screened by the operator. Built on Respark, which also runs customer win-back campaigns for local service businesses.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 3 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦ - KiniBuka
: Find small Indonesian UMKM stalls that are open right now: a live feed of openings, closings, promos and bazaars, a map with search, follow alerts, and order-ahead with a one-tap WhatsApp handoff.
β¨ Landing page Β· π README Β· π’ Updated Nov 3 Β· 2 commits this week Β· latest: docs: Filee-style hero for every app README (banner, live demo, downloaβ¦
22 tools in juw12/tools, plus a factory to build more (python3 toolbox.py new <name>)
Small, local and private: Python standard library only, no accounts, every tool has a self-test.
- Subscription Leak Finder
: Reads your bank CSV and finds hidden recurring charges, quiet price rises, trials that turned paid and overlapping services.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo subscription_leaks - Bank Fee Detector
: Finds overdraft, FX, ATM and maintenance fees, flags stacked overdrafts and drafts a refund request.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo fee_detector - Contract Red-Flag Scanner
: Scans a contract for auto-renewals, cancellation traps, data sharing and forced arbitration.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo contract_redflags - Shrinkflation Detector
: Catches shrinking packs that hide a real price rise by comparing price per unit over time.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo shrinkflation - Warranty Tracker
: Tracks warranties before they expire unnoticed and flags purchases with missing receipts.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo warranty_tracker
- Scam Message Checker
: Checks a message for phishing, fake parcel and 'Hi Mum' scams, including look-alike links.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo scam_check - Fake Shop Checker
: Spots fake online shops: irreversible payment methods, 80%-off 'closing down' scripts and an optional domain-age lookup.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo fake_shop_check - Rental Scam Checker
: Flags fake rental listings: pay before viewing, absent landlord, rent far below market.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo rental_scam_check - Voice-Clone Safe-Word Kit
: Sets up a family safe phrase and call-back rule against AI voice-clone 'emergency' calls.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo voice_clone_safeword - Fake Job Interview Lure Checker
: Detects fake-recruiter lures: 'run our repo' tests, ClickFix terminal commands, fake meeting links and moves to Telegram.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo job_lure_check - Interview Code-Test Triage
: Scans a take-home coding test without running it, for install hooks, VS Code auto-run tasks, credential theft and hidden payloads.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo code_test_triage
- GDPR / CCPA Deletion Request Generator
: Writes GDPR / CCPA deletion letters to data brokers and tracks their legal deadlines.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo privacy_requests
- Heat Risk Planner
: Uses the NWS heat index and a live forecast to plan safe hours for outdoor work.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo heat_risk - Hidden Water Leak Detector
: Finds hidden leaks from continuous night-time meter flow and estimates the yearly waste.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo water_leak - Energy Upgrade Payback
: Gives an honest payback, NPV and IRR for solar, heat pumps and insulation.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo energy_payback
- Caregiver Medication Planner
: Helps carers plan medication: run-out dates, a reorder list and a daily dose schedule.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo med_refills - Unclaimed Benefits Screener
: Screens US and UK benefits worth checking and points to the official calculators.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo benefit_finder
- Digital Legacy Planner
: Finds digital inheritance gaps (crypto, 2FA, heirs) and writes instructions for your executor.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo legacy_planner - Account Recovery Audit
: Maps how your accounts recover each other: SIM-swap blast radius, email chains and missing backup codes.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo account_recovery_audit - 3-2-1 Backup Auditor
: Audits your backups against the 3-2-1 rule and catches 'cloud sync is not a backup' and untested restores.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo backup_check - Bit-Rot Guard
: Detects silent file corruption using SHA-256 fingerprints.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo bitrot_guard - File Format Rescue
: Finds files stuck in dying formats and gives the exact command to convert each one.
β¨ Landing page Β· π README Β· βΆpython3 toolbox.py demo file_rescue
10 agent skills in juw12/skills: plain SKILL.md files for Claude Code, OpenCode, Codex and SkillMouse
Agents that verify instead of claiming: they run the checks, report honestly and stop when they should.
- refine-loop
: Improve-until-done without babysitting: frozen rubric, baseline score, separate judge, keep-best, blind A/B check against score inflation and hard stop rules. Ships an objective self-checker.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - harness
: Finds and actually runs a project's build, test and lint commands, and reports pass/fail truthfully.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - heartbeat
: A short, honest status of running jobs and services (servers, watchdogs, long tasks) that flags stalls.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - delegator
: Breaks a goal into small tasks, routes each to the best agent or skill, then combines the results.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - soul
: Reviews drafts, docs and UI copy against a project's voice and principles, with minimal fixes.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - memory-management
: Durable project memory (decisions, lessons, context) in an Obsidian vault, so it survives across sessions.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - widgettheme
: Applies "The Morning Paper" editorial design system: cream paper, ink black, newspaper red, serif headlines.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills
- beacon-push
: Send and inspect push notifications through Beacon: Web Push, FCM, ntfy, Bark, Gotify and Apprise.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - tether-android-qa
: Drive a real Android phone or emulator through Tether: read the screen, tap, type, swipe and read logcat.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills - push-qa-e2e
: End-to-end check: subscribe the phone, send a push, assert it shows in the shade, tap it and verify the app opens.
π SKILL.md Β· π README Β· β¬git clone https://github.com/juw12/skills
![]() Cozy Island: A cozy 3D island for laptop workers: fish, garden, take tea-breathing breaks and rest your eyes, with Mochi the cat. βΆ Play now Β· β¨ Landing page Β· π README |
![]() VALE: A first-person explorer: collect five Lumenshards to restore a fading fairy realm. βΆ Try it live Β· β¨ Landing page Β· π README |
![]() Game Library: A searchable collection of browser games by category, with a Surprise Me button. Runs offline in the browser. βΆ Play now Β· β¨ Landing page Β· π README |
![]() Townsquare 3D: A shared 3D town for phone and desktop browsers: claim land, run crops and workshops, trade at a market that follows supply and demand. βΆ Play now Β· β¨ Landing page Β· π README |
![]() Hearthwood: A third-person action-adventure prototype with dialogue, quests, inventory and NPC AI. β¨ Landing page Β· π README |
![]() Datum CAD: A PRD plus six reference photos becomes a validated STEP solid, with an STL preview. β¨ Landing page Β· π README |
![]() Explicit MacCormack Method: A computational fluid dynamics study of a predictor-corrector scheme, with plotted results. β¨ Landing page Β· π README |
![]() Upwind Differencing Scheme: A computational fluid dynamics study of upwind differencing, with plotted results. β¨ Landing page Β· π README |
2 workplace automations: small tools I use in the R&D day job
- PLM AML Approval
: Python + Playwright tool that walks a Windchill-based PLM part-approval (AML) workflow in Edge: it searches the part, starts the workflow, uploads the approval documents, fills the form, adds the reviewer, verifies every field and stops before Submit so a person makes the final check.
β¨ Landing page Β· π README - Outlook Archiver
: A small Windows daemon that keeps Outlook's Inbox and Sent Items empty by moving every message into an Archives PST, while logging each one and showing a desktop toast so nothing is missed.
β¨ Landing page Β· π README
Prompt packs and product experiments kept on record
- Handoff
: AI automation agency plus SaaS product for SMBs. Five Next.js apps, cold-outreach copy and a 14-day validation playbook.
β¨ Landing page Β· π README - 150 ChatGPT Prompts for Etsy Sellers: 150 copy-paste prompts across 9 sections, packaged as a 6-phase workflow that writes an Etsy listing in 5 minutes. PDF + Notion template.
β¨ Landing page Β· π README
The full monorepo: juw12/projects Β· All repositories Β· Landing pages
Every public project is released under the MIT License; contributions follow the Contributor Covenant and security policy.
Independent personal projects. No employer endorsement implied. Demos and prototypes vary in maturity; check each README before use.
If something here is useful, a β on the repo helps, and following @juw12 keeps you posted on what ships next.


















