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kappaemme Kappaemme-git

Building apps and tools.

CS student at Federico II. I am Francesco, aka Kappaemme. I build iPhone apps, websites and open-source tools, and share what I learn through Codex skills.

See my work Get in touch

Follow the build on X, read the code on GitHub, or send an email.

Portrait of Francesco Mistero

~/projects5 projects

Selected work.

A small gallery of products I build and maintain. Select a piece to explore it.

Metodo ZACiPhone app

Coach-led workouts, progress tracking and check-ins.

View on the App Store

VibeDeskWeb app

A study and work companion I am currently building.

Visit the website

More work

Explore all GitHub projects ↗
  1. 01 metodo ZAC · websiteCoaching programs, client journeys and the digital home for Metodo ZAC. WebsiteLive
  2. 02 pocketflowMinimal widget app for deep focus — tasks, timer and music. AppLive
  3. 03 glorydrawFantasy football app for drafting a World Cup dream team. Web appLive

~/skills10 featured

Codex skills, open source.

Recent releases and the open-source skills developers have starred most.

Most starred

  1. 01 codex-first-customer-finder-skillFind evidence-backed first customers and draft outreach from public signals. 1k+ stars
  2. 02 codex-startup-pressure-test-skillPressure-test startup ideas before building the MVP. 900+ stars
  3. 03 codex-complexity-optimizerAnalyze code complexity and identify safe performance improvements. 900+ stars
  4. 04 local-client-prospector-skillFind and qualify local businesses that could use a better website. 150+ stars
  5. 05 codex-bug-reproducerReproduce bugs and prove fixes with focused regression evidence. 70+ stars

Star counts refresh from GitHub on load.

Recent releases

  1. 06 astra-ad-studioCreate finished ads, campaign variants and motion previews inside Codex.
  2. 07 codex-code-avengersCoordinate six review roles for evidence-backed code reviews.
  3. 08 codex-dev-teamRun a five-role collaborative engineering workflow in Codex.
  4. 09 startup-feedback-engineTurn customer feedback into prioritized product opportunities.
  5. 10 app-store-review-guardianAudit an iOS app before App Store submission.

All repositories on GitHub ↗

See all skills

~/grok-bots2 bots

My Grok Bots.

Small bots I build and run inside Grok Bot. Each one does one job. The code is on GitHub.

Meet the bots

New ones land there first.

Librarykappaemme.dev/grok-bot

~/on-x5 quote posts

Shared by Greg Brockman.

Greg Brockman, OpenAI co-founder, quote-posted five of my Codex skill demos on X. Each card opens his original post.

5posts by Greg
1.8M+combined views
10K+likes
Greg Brockman @gdb codex for customer feedback → roadmap Kappaemme @Kappaemmedev

CODEX SKILL THAT TURNS CUSTOMER FEEDBACK INTO A ROADMAP!

Startup Feedback Engine ♡ 732138K viewsView on X Greg Brockman @gdb Codex for finding customers for your startup: Kappaemme @Kappaemmedev

CODEX SKILL THAT FINDS YOUR STARTUP'S FIRST CUSTOMERS!

First Customer Finder ♡ 3.7K692K viewsView on X Greg Brockman @gdb codex for improving computational complexity Kappaemme @Kappaemmedev

CODEX SKILL THAT FINDS COMPLEXITY HOTSPOTS IN YOUR CODEBASE!

Complexity Optimizer ♡ 1.7K331K viewsView on X Greg Brockman @gdb codex for finding local businesses who may need help building a website: Kappaemme @Kappaemmedev

CODEX SKILL THAT TURNS LOCAL SEARCH INTO CLIENT LEADS!

Local Client Prospector ♡ 1.5K292K viewsView on X Greg Brockman @gdb codex for startup ideas Kappaemme @Kappaemmedev

CODEX SKILL TO BRUTALLY TEST ANY STARTUP IDEA!

Startup Pressure Test ♡ 2.3K395K viewsView on X

Engagement figures checked on 23 September 2026.

~/stack12 tools

The stack.

The languages, frameworks and tools behind these projects.

  • Clanguage
  • Javalanguage
  • JavaScriptlanguage
  • Pythonlanguage
  • Reactframework
  • Electronframework
  • GitHubplatform
  • VS Codeeditor
  • Firebasebackend
  • PostgreSQLdatabase
  • Railwaydeploy
  • Stripepayments

~/journey2023 — present

The journey so far.

Computer Science at Federico II, and building in public since October 2025.

  1. 2023 — present

    Computer Science student

    Università degli Studi di Napoli Federico II

    • Computer Science student at Università degli Studi di Napoli Federico II.
    • 2024 experience at Apple Foundation.
    • Growing solid foundations in algorithms, systems, databases, and software engineering.
  2. October 2025 — present

    Indie hacker

    Building in public · @Kappaemmedev

    • Started in October 2025 and changed my mindset about software.
    • Built the Metodo ZAC iPhone app and website.
    • Published Codex skills used and starred by developers around the world.

~/coffeeSupport the build

Support the next build.

I build small digital products, test them in the real world, and keep improving. If something I make is useful to you, a small donation helps me keep shipping.

Buy me a coffee My work Contact me

Donations go through Stripe. More on the coffee page.

  1. BuildI ship small products fast.VibeDesk, ShipSlap and PocketFlow started from simple ideas, real usage and fast iteration.
  2. LearnI keep raising the bar.I study Computer Science at Federico II and use every project to sharpen the next one.
  3. RepeatYour support becomes momentum.Every small donation helps cover tools, experiments and the time to keep building in public.

~/contact

Got a project or an idea? Let's talk.

Open to collaborations, freelance work, or just a good conversation about shipping.