I hadn't touched computer programming until 2019, when a benevolent coworker took it upon himself to teach a few of us SQL, and got us access to the company's BigQuery instance.
We were working on a team focused on making outbound phone calls, one step removed from customer service. The company (a health insurance company, alas), had a robust data warehouse and sat on a trove of rich data. SQL was immediately applicable to my work, so I had lots of opportunities to practice.
From there, I learned some python basics from the same coworker, and have been intermittently self-studying ever since.
A calculator app that natively supports fractions and mixed numbers in an easy and intuitive way.
The impetus for developing this app was frustration with the relative difficult of doing simple arithmetic on fractions when wooodworking. This difficulty does not exist for anyone working with the metric system, but is inevitable when using US customary units (feet and inches).
In-Line Calculator
A browser extension designed to allow you to evaluate simple arithmetic expressions as you type.
You can watch a demo here.
SQL class
At a former job, I was interested in teaching some of my coworkers basic SQL in the same way that my former coworker had taught me. To that end, I prepared some notes for a class that I gave weekly for a short period. The notes are available on google docs.