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Show HN: A geofence-based social network app 6 years in development

My name is Adrian. I'm a Software Engineer and I spent 6 years developing a perimeter-based geofence-based social media app.<p>What it does:<p>- Allows you to load a custom perimeter anywhere on the geographic map (180° E and W longitude and 90° N and S latitude), to cover area any area of interest<p>- Chat rooms get loaded within the perimeter<p>- You can chat with people within the perimeter<p>I developed a mobile app that uses an advanced geofence-based networking system from 2013 to 2019. My goal was to connect users within polygon geofences anywhere in the world. The app is capable of loading millions of polygon geofences anywhere in the world.<p><a href="https://enterpriseandroidfoundation.com/assets/images/other/manhattan-polygon-geofences.png" rel="nofollow">https://enterpriseandroidfoundation.com/assets/images/other/...</a><p>But people didn't really have a need for this. So after failing, I spent the next 6 years trying new ideas to use FencedIn for. I tried a location-based video app and a place-based app that had multiple features. Nothing worked, but now I'm almost finished developing ChatLocal, an app that allows you to load a perimeter anywhere on the geographic map, which loads chat rooms.<p>The tech stack is 100% Java (low-level mostly). I have a backend, commons library and an Android app. Java was the natural choice back in 2013. However, I still wouldn't choose anything else today. Java is the best for long-term large-scale projects. (I'm also using WildFly. PostgreSQL and a Linux server.)<p>This app is still not fully finished, but I think the impact on society might be tremendous.<p>The previous app to ChatLocal, LocalVideo, is fully up on the Google Play store and can be tested. It has 88% of the features of ChatLocal, including especially the perimeter-based loading system.<p>The feedback I'm mostly looking for is new ideas and concepts to add to this location-based social media app. And how strong of a value proposition does the app have for society.

Show HN: A Daily Bible Game

I created a daily game where you get a random Bible verse and try to identify the book (e.g. "Psalms", "Genesis", "Luke") in as few guesses as possible.<p>I have absolutely no clue how I got the idea, other than the fact that I grew up in the Orthodox Church and all my other coding projects have been faith-related (a terrible mobile app (1) and slightly broken Byzantine chant website (2) ). I'm a relatively new developer and I've been hungry for a project to build that people will actually use and share around, so I hoped this would fit the bill.<p>Sure enough, friends and family have been making it part of their daily routine. When priests AND my nonreligious college friends started sending me their results every day, I knew I had <i>something</i>. It was really exciting.<p>------<p>When the idea popped into my head, I started working on it right away. I created the project at 1AM and had a MVP/SLC version done a few hours later. That was a few weeks ago.<p>I am using SvelteKit, no external APIs, and SQLite for the database. It's hosted on an Ubuntu machine in my living room. Coding agents like Roo/Kilo Code assisted heavily in the development, but after I had already decided on the overall architecture and how I wanted things to work together.<p>The game is free, has no signup, and I’m not running any ads. I’m looking for any and all feedback, and especially suggestions for how I can make the game more interesting, fun, and/or educational.<p>Thank you HN!

Show HN: macOS menu bar app to track Claude usage in real time

I built a macOS menu bar app to track Claude usage in real time via API after hitting limits mid-flow too often.<p>Signed and notarised by Apple. Open source.<p><a href="https://github.com/richhickson/claudecodeusage" rel="nofollow">https://github.com/richhickson/claudecodeusage</a><p><a href="https://x.com/richhickson" rel="nofollow">https://x.com/richhickson</a>

Show HN: macOS menu bar app to track Claude usage in real time

I built a macOS menu bar app to track Claude usage in real time via API after hitting limits mid-flow too often.<p>Signed and notarised by Apple. Open source.<p><a href="https://github.com/richhickson/claudecodeusage" rel="nofollow">https://github.com/richhickson/claudecodeusage</a><p><a href="https://x.com/richhickson" rel="nofollow">https://x.com/richhickson</a>

Show HN: VaultSandbox – Test your real MailGun/SES/etc. integration

I've spent the last few months working on something I wish I'd had years ago. I kept running into the same issue: CI green, production mail broken. TLS handshake failures, DKIM alignment mismatches, SPF soft-fails ... the stuff that only surfaces when real mail servers are involved. Most test tools (Mailpit, MailHog) are catch-alls. They confirm "an email was sent" but don't validate the protocol. They also aren't designed for network-exposed environments: no auth, unprotected Web UI, easy to enumerate messages.<p>VaultSandbox is my attempt at fixing that. It's a self-hosted SMTP gateway (AGPLv3) that validates SPF, DKIM, DMARC, and rDNS on every incoming message. You keep your production email provider (Postmark, SendGrid, SES) in tests and you just change the recipient domain. No mocking, no config changes. There are client SDKs (Node, Python, Go, Java, .NET), plus a Web UI and a CLI for manual testing.<p>Some technical details:<p>Deterministic Tests Instead of polling or sleep loops, the SDKs use Server-Sent Events (SSE) so test assertions trigger the moment the mail hits the gateway.<p>Minimal infrastructure footprint Built with NestJS and Angular, with no external database dependency to keep the container footprint small and easier to reason about.<p>Post-Quantum Encryption I use ML-KEM-768 for the encryption layer. Incoming mail is encrypted immediately using a client-generated public key and the plaintext is discarded. The server only ever stores encrypted message data and cannot decrypt it. I chose PQ because I wanted to build something I wouldn't have to revisit in five years. If it handles large PQ keys reliably, everything else is easy.<p>Quick start: <a href="https://vaultsandbox.dev/getting-started/quickstart/" rel="nofollow">https://vaultsandbox.dev/getting-started/quickstart/</a><p>Site: <a href="https://vaultsandbox.com" rel="nofollow">https://vaultsandbox.com</a><p>I'd love feedback, especially on whether AGPLv3 would be a blocker for something you'd self-host in dev.

Show HN: VaultSandbox – Test your real MailGun/SES/etc. integration

I've spent the last few months working on something I wish I'd had years ago. I kept running into the same issue: CI green, production mail broken. TLS handshake failures, DKIM alignment mismatches, SPF soft-fails ... the stuff that only surfaces when real mail servers are involved. Most test tools (Mailpit, MailHog) are catch-alls. They confirm "an email was sent" but don't validate the protocol. They also aren't designed for network-exposed environments: no auth, unprotected Web UI, easy to enumerate messages.<p>VaultSandbox is my attempt at fixing that. It's a self-hosted SMTP gateway (AGPLv3) that validates SPF, DKIM, DMARC, and rDNS on every incoming message. You keep your production email provider (Postmark, SendGrid, SES) in tests and you just change the recipient domain. No mocking, no config changes. There are client SDKs (Node, Python, Go, Java, .NET), plus a Web UI and a CLI for manual testing.<p>Some technical details:<p>Deterministic Tests Instead of polling or sleep loops, the SDKs use Server-Sent Events (SSE) so test assertions trigger the moment the mail hits the gateway.<p>Minimal infrastructure footprint Built with NestJS and Angular, with no external database dependency to keep the container footprint small and easier to reason about.<p>Post-Quantum Encryption I use ML-KEM-768 for the encryption layer. Incoming mail is encrypted immediately using a client-generated public key and the plaintext is discarded. The server only ever stores encrypted message data and cannot decrypt it. I chose PQ because I wanted to build something I wouldn't have to revisit in five years. If it handles large PQ keys reliably, everything else is easy.<p>Quick start: <a href="https://vaultsandbox.dev/getting-started/quickstart/" rel="nofollow">https://vaultsandbox.dev/getting-started/quickstart/</a><p>Site: <a href="https://vaultsandbox.com" rel="nofollow">https://vaultsandbox.com</a><p>I'd love feedback, especially on whether AGPLv3 would be a blocker for something you'd self-host in dev.

Show HN: Make audio loops online

I created a small webapp, to create simple audio loops online. A bit rough around the edges but gets you started in less than 10 seconds on creating loops.

Show HN: Stash – Sync Markdown Files with Apple Notes via CLI

Show HN: I visualized the entire history of Citi Bike in the browser

Each moving arrow represents one real bike ride out of 291 million, and if you've ever taken a Citi Bike before, you are included in this massive visualization!<p>You can search for your ride using Cmd + K and your Citi Bike receipt, which should give you the time of your ride and start/end station.<p>Everything is open source: <a href="https://github.com/freemanjiang/bikemap" rel="nofollow">https://github.com/freemanjiang/bikemap</a><p>Some technical details: - No backend! Processed data is stored in parquet files on a Cloudflare CDN, and queried directly by DuckDB WASM<p>- deck.gl w/ Mapbox for GPU-accelerated rendering of thousands of concurrent animated bikes<p>- Web Workers decode polyline routes and do as much precomputation as possible off the main thread<p>- Since only (start, end) station pairs are provided, routes are generated by querying OSRM for the shortest path between all 2,400+ station pairs

Show HN: I visualized the entire history of Citi Bike in the browser

Each moving arrow represents one real bike ride out of 291 million, and if you've ever taken a Citi Bike before, you are included in this massive visualization!<p>You can search for your ride using Cmd + K and your Citi Bike receipt, which should give you the time of your ride and start/end station.<p>Everything is open source: <a href="https://github.com/freemanjiang/bikemap" rel="nofollow">https://github.com/freemanjiang/bikemap</a><p>Some technical details: - No backend! Processed data is stored in parquet files on a Cloudflare CDN, and queried directly by DuckDB WASM<p>- deck.gl w/ Mapbox for GPU-accelerated rendering of thousands of concurrent animated bikes<p>- Web Workers decode polyline routes and do as much precomputation as possible off the main thread<p>- Since only (start, end) station pairs are provided, routes are generated by querying OSRM for the shortest path between all 2,400+ station pairs

Show HN: I visualized the entire history of Citi Bike in the browser

Each moving arrow represents one real bike ride out of 291 million, and if you've ever taken a Citi Bike before, you are included in this massive visualization!<p>You can search for your ride using Cmd + K and your Citi Bike receipt, which should give you the time of your ride and start/end station.<p>Everything is open source: <a href="https://github.com/freemanjiang/bikemap" rel="nofollow">https://github.com/freemanjiang/bikemap</a><p>Some technical details: - No backend! Processed data is stored in parquet files on a Cloudflare CDN, and queried directly by DuckDB WASM<p>- deck.gl w/ Mapbox for GPU-accelerated rendering of thousands of concurrent animated bikes<p>- Web Workers decode polyline routes and do as much precomputation as possible off the main thread<p>- Since only (start, end) station pairs are provided, routes are generated by querying OSRM for the shortest path between all 2,400+ station pairs

Show HN: I built a "Do not disturb" Device for my home office

Show HN: I built a "Do not disturb" Device for my home office

Show HN: I built a "Do not disturb" Device for my home office

Show HN: SMTP Tunnel – A SOCKS5 proxy disguised as email traffic to bypass DPI

A fast SOCKS5 proxy that tunnels your traffic through what looks like normal SMTP email, bypassing Deep Packet Inspection firewalls.<p>How it works: - Client runs a local SOCKS5 proxy (127.0.0.1:1080) - Traffic is sent to server disguised as SMTP (EHLO, STARTTLS, AUTH) - DPI sees legitimate email session, not a VPN/proxy<p>Features: - One-liner install on any Linux VPS - Multi-user with per-user secrets and IP whitelists - Auto-generated client packages (just double-click to run) - Auto-reconnect on connection loss - Works with any app that supports SOCKS5<p>Tech: Python/asyncio, TLS 1.2+, HMAC-SHA256 auth<p>GitHub: <a href="https://github.com/x011/smtp-tunnel-proxy" rel="nofollow">https://github.com/x011/smtp-tunnel-proxy</a>

Show HN: SMTP Tunnel – A SOCKS5 proxy disguised as email traffic to bypass DPI

A fast SOCKS5 proxy that tunnels your traffic through what looks like normal SMTP email, bypassing Deep Packet Inspection firewalls.<p>How it works: - Client runs a local SOCKS5 proxy (127.0.0.1:1080) - Traffic is sent to server disguised as SMTP (EHLO, STARTTLS, AUTH) - DPI sees legitimate email session, not a VPN/proxy<p>Features: - One-liner install on any Linux VPS - Multi-user with per-user secrets and IP whitelists - Auto-generated client packages (just double-click to run) - Auto-reconnect on connection loss - Works with any app that supports SOCKS5<p>Tech: Python/asyncio, TLS 1.2+, HMAC-SHA256 auth<p>GitHub: <a href="https://github.com/x011/smtp-tunnel-proxy" rel="nofollow">https://github.com/x011/smtp-tunnel-proxy</a>

Show HN: Jax-JS, array library in JavaScript targeting WebGPU

Show HN: Jax-JS, array library in JavaScript targeting WebGPU

Show HN: Mantic.sh – A structural code search engine for AI agents

Author here! Some context: I published this 48 hours ago and it was auto-listed on MCPMarket (the MCP tools directory). Got 700+ organic downloads with zero marketing—developers were actively searching for exactly this solution.<p>The "Git Accelerator" optimization story:<p>Initially used a file walker that took 6.6s on Chromium. Profiling showed 90% was filesystem I/O. The fix: git ls-files returns 480k paths in ~200ms. Added smart heuristics for untracked files (only scan dirs <50k files), bringing total to 0.46s.<p>Why this matters: Agents can't wait 10 seconds for search. Sub-500ms makes it feel instant, changing how they explore codebases.<p>Installation:<p><pre><code> Cursor: npx mantic.sh@latest VS Code: npx mantic.sh@latest CLI: npm i -g mantic.sh </code></pre> Limitations: Mantic is optimized for precise queries ("find stripe webhook") where structure matters. For fuzzy exploratory search, traditional embeddings may still be better. Curious if HN has ideas for hybrid approaches.<p>Happy to answer questions!

Show HN: Mantic.sh – A structural code search engine for AI agents

Author here! Some context: I published this 48 hours ago and it was auto-listed on MCPMarket (the MCP tools directory). Got 700+ organic downloads with zero marketing—developers were actively searching for exactly this solution.<p>The "Git Accelerator" optimization story:<p>Initially used a file walker that took 6.6s on Chromium. Profiling showed 90% was filesystem I/O. The fix: git ls-files returns 480k paths in ~200ms. Added smart heuristics for untracked files (only scan dirs <50k files), bringing total to 0.46s.<p>Why this matters: Agents can't wait 10 seconds for search. Sub-500ms makes it feel instant, changing how they explore codebases.<p>Installation:<p><pre><code> Cursor: npx mantic.sh@latest VS Code: npx mantic.sh@latest CLI: npm i -g mantic.sh </code></pre> Limitations: Mantic is optimized for precise queries ("find stripe webhook") where structure matters. For fuzzy exploratory search, traditional embeddings may still be better. Curious if HN has ideas for hybrid approaches.<p>Happy to answer questions!