I build the tools on diytools.io alone, in evenings and weekends, because most personal-finance software is bloated, signup-walled, or built to harvest your data. I wanted none of that — so I started making the tools I needed myself.
The first tool was Wealth Reflection — a calculator that just shows you where you stand. It runs entirely in your browser; nothing leaves your laptop.
When a tool needs an account, the company is the customer and you are the inventory. These tools don't need accounts. The math runs on your device.