Retired from the railway. Now I build things.
I'm Mark, soon to be writing this from Cyprus. After a career in London Underground operations, then training delivery and design, I now spend my time making browser puzzles, an iPad colouring app, and whatever catches my interest next. Everything here is made at home with a lot of help from Claude, free where it can be, and honest about what it is.
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Browser puzzles, rotating daily
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Colouring pictures in Tintl
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Adverts, accounts or trackers on puzlr
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puzlr
Eleven browser puzzles that rotate daily — Kurosu, Slitherlink, Hashi and friends, each with graded difficulty and every puzzle proved to have exactly one solution. Free, no accounts, no tracking, permanently. Play at puzlr.co.uk, or read more.
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Tintl
A therapeutic colouring app for iPad: tap-to-fill vector line art across thirteen categories, from mandalas and stained glass to landscapes and fantasy scenes, with proper brushes for freehand work. Heading for the App Store — more here.
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Lucky Dip
A free lucky-number generator with one-tap presets for EuroMillions, Lotto, Thunderball and more, picked by a three-stage shuffle rather than a plain random number. Works offline, no tracking. Dip in at luckydip.me, or read more.
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Iron Log
A simple weight-training tracker that keeps everything on your device — log the lift, see the trend, no account and nothing sent anywhere. Now on the App Store — more here.
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Digital tabletop railway
The project I'm proudest of: a working miniature of the Underground built for operations training, so staff can practise procedures on a railway that fits on a table. Have a look.
All of my apps are coming to Android soon.
A career of getting the details right
I spent my career on London Underground — first in operations, then delivering and designing training across every role the railway runs on. The crowning glory was the digital tabletop railway built for operations training — a working miniature of the network to learn on. I retired in July 2026 and kept the habit: everything above is built the same way, checked against the evidence before it ships.
