if it's used a standalone app then what functionality is it providing beyond "user admin". Like, what problem does it solve in that use case?

> a Go framework/toolkit that enables you to build your own custom app specific business logic

that definition applies to literally every framework and toolkit. It tells me nothing.

> and still have a single portable executable at the end.

You're quoting selectively in a way that elides meaningful parts of the sentence, and then stating that the description lacks meaning.

It provides an authenticated rest API (with a premade JavaScript client library) to an sqlite database, so you can store users' data similarly to how you might use firebase.