Here is a list of iPhone apps that I currently—or hopefully soon—have on the Apple App Store. They all have two things in common: they're free, and they're apps I myself like to use. Given how low vibe-coding has made the barrier to creating mobile apps, that second one is increasingly the only reason for making them. It's still nice to make them easily available to others as well.
They're built with React Native and especially the Expo framework, of which I'm a huge fan.
Learn and quiz yourself on big chunks of history—Greece & Rome, Nazi Germany & WWII, Science & Physics and more. Every topic gives you four ways in: Explore it decade by decade with images and maps, scan it as a Table, see it on a zoomable Timeline where wars and reigns stack as bands above the individual events, or take a Quiz on it. Free, flexible and comprehensive—same philosophy, and deliberately the same UI, as Geography Learner.
Study and test yourself on the countries, capitals and flags of the world—plus finer-grained sets like Europe's 38 countries, Belgium's 11 provinces and Italy's 20 regions. Each topic comes with an interactive map, a browsable list, flashcards and a configurable quiz (pick what gets asked, and whether you play a "3 lives" survival run or a fixed-length one). Favourites let you star items across topics for targeted review.
Reconstruct your own life on a zoomable timeline. Its tagline is "fill the gaps": you drop in the moments and periods you remember—jobs, homes, relationships, trips—tag them by category, attach photos whose place names are read straight from the photo's own metadata, and the app shows you which entries overlapped, so a trip automatically surfaces the house you lived in and the job you had at the time.
Named with deliberate cheek. It's a general "manage your stuff" app: define your own item types, then build a home screen out of widgets—calendar, weather, statistics, quick-add. Basically a pocket-sized take on the highly customisable database apps I've always liked, from Airtable to classic Salesforce and ERP platforms. A coming-home vibe-coding exercise that turned into something I actually use.
For drawing the exact route you want to run, and then going out and running it. Sketch it on the map, adjust it until the distance is right, and set off. It comes into its own for runs with a buddy: pick a meetup point that works for both of you, each get your own leg to it, then run the shared stretch from there together—and split off again at the end. Planning a route this specific normally means fighting a website on a laptop; here it's a few taps on a phone.
Keeps your close circle on the radar: who you've seen lately, who you haven't, ideas for catching up, and an easy way to get the next meetup on the calendar. A personal CRM of sorts, but pointed at friends and family rather than a professional network—and much heavier on the calendar. Expo and React Native on the front, Express.js on Google Cloud behind it.
The one that started the mobile habit, a decade before the rest of this list. A companion app for the Unigift city-voucher programs, letting residents browse participating merchants, check where their gift voucher is accepted, and keep it to hand while shopping nearby—kept in sync with the same backend the municipalities administer through. Still running alongside the live voucher ecosystem.
These are just the mobile ones. There's a much longer list of experiments, prototypes and production platforms on the projects page.