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, free where it can be, and honest about what it is.
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Browser puzzles, rotating daily
1,760
Colouring pictures in Tintl
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Adverts, accounts or trackers on puzlr
01
puzlr
Ten 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.
02
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.
03
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.
04
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 operational roles. 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.
