Some software has to keep working after the first release, in the hands of people the original brief never met. The interesting question is how it was shaped so that could happen.
This note is about that kind of work: a product or plugin with a public footprint, where the contribution has to be described accurately. A usage figure is easy to borrow from a marketplace and easy to overstate. This page will cite a public source, and it will say what was actually built, before any user count is published.
What the work focused on
Clear boundaries in the product. Predictable behavior when other systems connect to it. A release path that does not depend on one person remembering the steps. Documentation a later contributor can follow.
Those are the parts a founder can judge. A large install count, once it is sourced, is context. It is not a substitute for knowing what changed and why.