How I decide whether to continue or kill a SaaS project

I’m building multiple small SaaS projects, and I kept running into the same problem:

Building wasn’t the hard part.
Deciding whether a project was worth continuing was.

Most of the time, I relied on gut feeling:
– some stats here
– Stripe data there
– a few notes in my head

So I built a very simple internal tool called SaaSBoard.

It centralizes basic signals per project:
– activity / usage events
– early feedback
– early revenue (if any)

The goal isn’t analytics or optimization.
It’s just to answer one question faster:

Should I keep working on this, or stop?

I’m curious how others here handle this.
What signals do you personally trust most when deciding to continue or kill a project?