How to get Business Logic from legacy app

Hi,

We acquired an app written in Ruby a few years back. Unfortunately there was little to no documentation supporting the business logic available. And now all previous owners, developers have since left.

I need a tool to extract the business logic from the app.

We tried ../github.com/mariusandra/aristotle   but see that it is out dated.

Please can someone help guide me to a newer/current version of Aristotle or an alternative.

Thanks in advance,

Larry