Is Rentometer a good tool to help calculate rent?

I’ve seen different article talking about Rentometer as a go-to tool to help calculate rent and some other articles giving other options. I don’t have the time to chase down listing on Craigslist and Zillow and other listing sites. I want to be able to go to one source and get accurate information I can trust.

I have found the free tool to be helpful as a baseline for rent amounts. Is the Pro version with it?