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One of the absolutely coolest features of Kidz Fun Art is the ability to create Animations. This was initially inspired by watching my nieces creating an animation on another Android app, so I focused purely on the creation case. This worked well, where most animations were under 50 frames in length, as it takes time to create them. I later added the ability to import Gif images, since it was a relatively simple change – parse the Gif image into frames, save them and boom, you can edit and re-export it. However this exposed a problem: Gifs can be huge, and Kidz Fun Art didn’t work well with thousands of animation frames of data. I wasn’t sure where the bottlenecks were, but at some point the app would just crash if the Gif was big enough, of if the user created an animation over 100 frames or so. This is all now fixed, and the app comfortably imports multi-Megabyte Gif images and provides a better user experience when some operations (like deleting hundreds of frames) are not instant. Using AI to find performance issues & subtle bugs While I have always written the vast majority of the code for Kidz Fun Art by hand (using AI for more complex things like WebGL shaders and C++ based paint brush simulation), it’s been invaluable recently for reviewing and testing the code. I asked Claude Opus 4.8 (the current frontier model as of July 2026) to identify the bottlenecks and it did a great job. There were multiple places where I initially wrote a function to take an action on a single frame that would then save the full animation, but later reused this function in a loop over all the frames. This caused the full animation to be saved hundreds of times in a few seconds, crashing the app. The list of frame thumbnails at the bottom of the screen rendered all thumbnails up front. This is fine for 50 but not for 1000. When saving a Gif, the file was far too large. This is because it wrote each frame in its entirety to the Gif image. The Gif standard obviously supports just writing the pixels that changed from the previous frame, and I wasn’t doing that. Deleting a large animation would take multiple seconds, with not user feedback. This was fine for other media types as they are more or less instant, but in this case it let the user click around the app, then have unexpected things happen 5 seconds later. It made the app feel broken. Gifs that stored some frames with the option to simply restore the previous frame were not handled, making the import of some images be inaccurate. There were a number of places where race conditions between multiple asynchronous actions could cause bugs. The AI was very good at finding places where my code should have been waiting for one to complete before beginning the second. There were multiple places where memory leaks occurred, specifically with not cleaning up event listeners. It found them all. When leaving the app open for days or weeks at a time without a reload, this could have been a real problem. What is better now? Animations now scale up to very large sizes, with instant access to all frames. You should be able to import basically any reasonable Gif image, and it will be exported in a highly optimized manner, with perfect colour matching per pixel. When deleting a large animation, you are told it is being deleted immediately, so it’s obvious the app is doing what you asked it to do. When importing a large Gif, you are shown a dialog telling you that it is happening, and blocking you doing other work until that completes. Many subtle bugs fixed. The frame list is fully virtualized, and scales up to essentially any size of animation. We have tests now! Another great use of AI is for writing tests, in this case laboriously creating dozens of large integration tests. These were invaluable in both validating the deep changes being made and in finding more edge cases and race conditions. Kidz Fun Art now has full end-to-end tests covering animations, layers, comics, cards, drawing, colouring, handwriting, maths and puzzles. I hate writing these, but AI doesn’t get bored, and I look forward to adding more and more regression tests in the future to keep quality high for all the world’s young artists out there.
For a long time I’ve wanted to add Spirographs to my (awesome ) drawing app for kids, Kidz Fun Art, and today it’s ready! There was quite a bit of fun mathematics in getting it to feel natural and work with all sizes of circles, but it seems to have worked out very well! You can move the Spirograph around, change the size of the outer and inner circles, and draw in any colours you like. Read more about it on the main blog post here, try it out on the web at https://kidzfun.art , get it for iPad here, or download for Microsoft Windows here.
Way, waaayyy back in 2010, I built a fun little game for the Palm WebOS series of phones called Mazer. I was happy with it, loads of people downloaded and played it, and then WebOS died. I recently found the source code again, and with the help of Claude AI I rewrote it to run on iOS and iPad! Get it for free today from the iOS App Store. (Android version coming soon) There are four different game types You can find your way around a simple maze, or race a terrifying fiery ball to the finish. Over 120 hand crafted obstacle courses to get around with worm holes, force fields, evil fiery balls, and more. My personal favourite, a Pacman like maze where the four ghosts chase your little ball around as you try to open the portal and get outta there!
I’ve been using the Irish energy provider Energia for 5 years or so (as of writing, 2026) and they used to have a useful insights dashboard that let me analyse my power usage. Well, they seem to have removed it so I built a handy dashboard that anyone can use. It’s at https://energy.chofter.com/ , try it out! You simply download your power usage information as a CSV file (a spreadsheet) from their site, currently at https://energyonline.energia.ie/my-account/half-hourly-usage/ . Then drop the file into the web app and it will: Show a useful overview of your usage for the full time period You can configure your current home setup This includes specifying your current tariff, whether or not you have a home battery or a car Compare usage versus last year Shows a heatmap of your usage by every 30 minutes Simulate the change in cost if you change your home setup Try out what would happen if you kept your consumption the same but changed your tariff, or added a battery or a car. This one is particularly useful.
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I owe a lot of my professional identity and success to CSS-Tricks. CSS-Tricks repeatedly gave me the opportunity to write for them. In doing so, they helped to both socialize and normalize accessibility as a mainstream frontend concern. I’m deeply thankful to them for this. The team was also a joy to work with, notably Geoff Graham. He’s a mensch, and one of the nicest people you can interact with in the frontend web space. If you have not been following the news about the site, Kevin Powell has a good video about the whole situation: Content skipped. I’m not speaking on behalf of Geoff, Chris, or others involved with running the current version of CSS-Tricks. I’ve got skin in the game as an author. This is my personal opinion, born of my feelings and beliefs. I think a lot of the web’s infrastructure should be co-ops, and CSS-Tricks is knowledge infrastructure. To that point, I should also point out that the website covers far more than just CSS. The corporate model of ownership can be a risk. If infrastructure is not part of a corporation’s core strategy, it is not a priority. As Kevin’s video touched on, it seems like promotion via owning the frontend content space isn’t part of Digital Ocean’s strategy anymore. It is not that CSS-Tricks does not have value. It is that Digital Ocean cannot see it. It is deeply, tragically ironic to me that Digital Ocean allowed this to transpire. This is because I know for a fact that the techniques and philosophies shared by CSS-Trick authors helped to shape iterations of their product’s UI. Some may be quick to point out that this knowledge now—illegally—exists inside of LLM training data, so the risk of the website going away is mitigated. To this, know that we should be striving to keep resources like CSS-Tricks going. Human creativity is the force that creates new techniques, strategies, and technologies. The web will calcify without voices sharing what they know, forever locking us into endless permutations of a fixed point in time. Unlike corporations, co-ops don’t have to be motivated by profit. By not needing to prioritize growth at all costs it means co-ops can instead prioritize and incentivise things like preservation and cultivation. It is also a successful model of operation, one that even already exists, and flourishes in the tech space. Collective ownership can also serve as checks and balances for, and protection against hierarchical decision-making. I only need to point to the chaotic and aberrant decisions many CEOs in the technology space have been making as of late to demonstrate the value of this approach. Paddy Srinivasan, if you somehow wind up reading this: Save some face and take a big swing. Give CSS-Tricks back to the people who love it.
Neat set of hacks lets you run any NixOS package in a browser hosted VM
How can something that “just works” be so annoying? situation We live in Cambridge off a little road down a drive in shared ownership between us and our neighbouring houses. All the utilities are buried under this drive, including the phone line. anticipation Over the last few years we have been canvassed repeatedly by CityFibre saying that they can deliver fibre all way to our house. I saw them digging trenches and leaving tails of purple fibre cladding along nearby roads, ready to hook up all the houses. I thought they would need to do something similar to deliver fibre to us. So when they turned up and knocked on our door, I talked to their salesbods and walked them up and down the drive and pointed out where the existing BT line goes. Then they gave up trying to sell to us. This happened about three times. disaffection We were not eager enough for an upgrade to deal with these impediments. notification A few months ago we were told that CityFibre would soon come and do the upgrade, since there’s a nationwide deadline for turning off the copper phone network at the end of the year. We expected that this would force them to actually plan some digging works, so we talked to our neighbours about it. We were all ready for some huge faff to follow the next visit by the CityFibre bods. installation CityFibre turned up on the promised morning bright and early. To our enormous surprise, a brown fibre housing was already poking out of the ground next to our copper phone line. It had been fed through 50 metres of 5cm duct without us being aware they were even working on the street. Within a couple of hours, the technicians had drilled through our wall, installed the ONT, blown fibre through the unexpected pipe, plugged in the CPE (superficially identical to the old one), and left telling us to anticipate that it might not work properly until tomorrow. activation Around lunch time, the copper phone line stopped working completely. Some faff ensued, switching all our devices over to the new WiFi network. For a while we thought this was the death of our land line, but in the course of debugging other issues, I realised that the router has a built-in VoIP adapter (I don’t think we were told it has a built-in VoIP adapter) so I plugged the phone in and it Just Worked: they had ported our phone number across and everything. Flawless. I was seriously impressed. rumination It has been a few weeks since the switchover, and apart from a couple of horrible Clown-afflicted IoT devices, it has been fairly smooth. What prompted me to write this up was realising that we delayed this upgrade for years because the sales people were not given enough technical information about how the installation process works: the fact that houses typically have a 5cm duct containing the copper lines (probably standard for the last 40 years) and the fact that fibre can be shoved through a few tens of metres without difficulty. And worse, the sales people didn’t have an esclation path for difficult cases: they just gave up instead. From a technical point of view, the installation was impeccable. (I guess the loose 24 hour window for the cutover time was because OpenReach and CityFibre don’t have tight requirements on ISP reconfiguration schedules.) From the sales point of view, it was crap. Maybe it would have gone faster if we offered to switch early without asking if the drive would be a problem? But I guess the difference between “yes!” and “yes, but will this be a problem?” is too much to expect from a minimum-wage door-to-door salesbod whose employer didn’t give them enough information or any escalation path.
