Ask HN: What Are You Working On? (April 2026)

I got addicted to scrolling content on my phone, so I built a digital pet whose growth and well-being depends on you staying off your phone! This way, if I spend all night scrolling the browser, my pet will get depression.

Unlike similar apps such as Focus Friend or Forest, which use active timers to police screen time, my app is an inversion that works like an idle game; All screen time is tracked all day, (with double the punishments at night), and upon check-in, you get feedback on your device usage.

A free and open source language learning app in the form of a pixel-art game - it currently supports 6 languages. It's something I feel Duolingo should've been but I've seen them drift further and further from the point. The app is fully offline and there's no accounts or signup

I'm working on a fully offline, client-side train journey planner for UK rail - https://railraptor.com

When booking flights, I use sites like Kiwi and Skyscanner that let you do flexible searches - multiple destinations, custom connections, creative routes, etc. But rail search feels oddly constrained. All the UK train operators offer basically the same experience, and surface the exact same routes. I always suspected there were better or just different options that weren’t being shown. Where is the "Skyscanner for trains"?

After digging through the national rail data feeds, I decided to have a go at building my own route planner that runs completely offline in the browser. This gave me the freedom to implement more complex filters, search to/from multiple stations, and do it without a persistent network connection.

Now I'm finding routes that aren't offered by the standard train operators, connecting at different stations, and finding it's often easier to travel to different stations (some I'd never heard of) that get me closer and faster to where I actually want to go!

It's still a little rough and I'd like to add more features such as fares, VSTP data, and direct-links to book tickets, but wanted to share early and get some initial feedback before investing more time into it. So, thanks in advance - let me know what you think.

This sounds very nice! A slightly adjacent question: have you discovered any providers that can recommend train journeys based on price? Sort of like the explore feature you find on sites like Google Flights, Ryanair and Flixbus. Sometimes when the wanderlust hits I've tried searching around for cheap train tickets, but it isn't simple using sites likes DB/OEBB/SBB/SNCF/etc

I'm looking at how to add price data to railraptor, but it might mean sacrificing the fully-offline capability... once I have prices it should absolutely be possible to build a filter along the lines of "find me the cheapest popular destinations that are at least 50 miles away".

After winning the Playlin Player's Choice award I've noticed an uptick in players as well as some people sharing videos on YouTube which has been fun. I've got a few thousand people playing every day.

I just launched user accounts today so user's can now track their progress across devices and share their stats with each other. This ended up being a bigger chunk of work than I expected but I'm really pleased with how it turned out. (Though I launched it 15 minutes ago so I'm holding my breath for bug reports)

I'm fine-tuning my internal puzzle-building now with the goal of letting people use them to make and share their own puzzles soon!

Coding agent that seems to beat Claude Code on SWE-bench at half the cost.

8/15 on SWE-bench Verified vs Claude Code's 5/15, ~$0.06/instance vs ~$0.12. Small sample, single repo, lots of caveats. But the direction feels right.

Event-sourced reducer, no framework deps beyond the Anthropic SDK.

I am working on making grocery online shopping less overwhelming and more like a rolling list, you keep adding items as you see them (missing) in your household and it silently records it at the backend. When you are ready to pick up order, you push to qfc cart via api (a button) and boom your grocery shopping is done. No need of making lists and then one by one putting them on the cart. It works with any QFC or Kroger store because to my disbelieve they actually have an open sku and cart api. Grateful to Kroger to be tech forward. Free to use , here is the link https://www.ddisco.com/sonic/customer My wife is hooked on it as she had to take time in the week to sit down ask me what to order and then build the cart. Now it’s like just typing in what you need.

Next I am making the version for folks who do not make a list and just go with past orders , for them I am automating so the cart is made based on past orders like milk usually is ordered every 2 weeks.

I built an open dataset mapping the structural connections between Israel's tech/startup ecosystem and its military-intelligence apparatus.

The Israeli tech industry isn't a neutral commercial sector, it's a deliberate pipeline from intelligence units to billion-dollar companies. Wiz ($32B Google acquisition) was founded by four Unit 8200 veterans. SoftBank's Israel ops are run by a former Mossad director. CyberStarts, a $1.5B VC fund, openly recruits Unit 8200 graduates.

I threw this app together the other day based on some feedback about bike kit sizing. You give it a brand, fit/line and current size and it will tell you what size you are in another brand. The body dimensions tool is still a bit rough. https://bikekitfit.vercel.app/

I am open to additional feedback. If you have points of comparison or would like a brand added please let me know in the comments!

A complete guide on how to travel or live by van in Japan. Additionally trying to turn my passion into a revenue by offering tourists custom handcrafted plans for them to travel.

This is a fun side project as I learn great with email communication, culture differences (as a dev)

I'm creating a new OS image for UniBone/QBone based on BuildRoot and a streamlined kernel. My goal is sub-five second boot time so you can get to using the host PDP-11 pretty much right away.

Crossed 100K MRR as a solo founder for Zigpoll[1] - honestly I never thought I would get this far with the product so now it's all about trying to market and keep growth strong. Doubling YoY gets harder each year so you always have to find new growth channels (or ways to improve existing channels). This is an interesting task especially given the current environment.

I used to think "if you build it they will come" but, as it turns out, it's much more nuanced than that and requires a lot of iterating and stumbling along the way. I hope to break into another vertical this year!

It's an iOS app that applies various generative art effects to your photos, letting you turn your photos into creative animated works of art. It's fully offline, no AI, no subscriptions, no ads, etc.

I'm really proud of it and if you've been in the generative art space for a while you'll instantly recognise many of the techniques I use (circle packing, line walkers, mosaic grid patterns, marching squares, voronoi tessellation, glitch art, string art, perlin flow fields, etc.) pretty much directly inspired by various Coding Train videos.

Hey, I've been getting into visual processing lately and we just started working on an offline wrapper for Apple's vision/other ML libraries via CLI: https://github.com/accretional/macos-vision. You can see some SVG art I created in a screenshot I just posted for a different comment https://i.imgur.com/OEMPJA8.png (on the right is a cubist plato svg lol)

Since your app is fully offline I'd love to chat about photogenesis/your general work in this area since there may be a good opportunity for collaboration. I've been working on some image stuff and want to build a local desktop/web application, here are some UI mockups of that I've been playing with (many AI generated though some of the features are functional, I realized that with CSS/SVG masks you can do a ton more than you