Hi, I'm Jon.
Learning out loud.
A quiet corner of the internet for the small apps I build for fun, useful references and study notes, and the occasional thing I write down.
Apps
// things I vibe-coded
Retirement Calculator ↗
Model retirement savings with additional contributions and drawdown modes.
Congkak ↗
Play the traditional Malay mancala game — vs a friend or the computer, with a best-move solver.
Rush Hour Solver ↗
Solve Rush Hour puzzles with step-by-step move guidance.
NAPFA Calculator ↗
Calculate NAPFA scores for Singapore primary and secondary students.
Quadratic Graph Explorer ↗
Explore quadratic graphs step by step — built for Sec 2 Maths.
Investment Backtester ↗
Backtest DCA and crash-buying strategies with XIRR and drawdown metrics.
Health Assessment ↗
Track and assess personal health metrics in one place.
Judges Timeline ↗
Interactive timeline of the judges in the Book of Judges.
Resources
// references, notes & cheat sheets
Blog
// notes & write-ups
About
// whoami
I'm someone who likes learning — Apologetics, investing, communications, health, science, tech, AI, etc., building small useful apps, and writing down what sticks. By day I'm an IT auditor based in Singapore, holding the CISSP, CCSP, CISM and CISA certifications.
A Christian, passionate about personal and organisational development, communication, and leadership — also a Maxwell Leadership Certified Team Member and Maxwell Certified DISC Consultant.
This is where I keep it all in one place.