Repology might kinda help for your use case. It lets you search for software that is packaged on many different “families” of distributions. You can also filter by category.

Admittedly it does kinda depends on your definition of popularity. But it’s good at answering these questions:

• Is this widely regarded as free software?
• Has it been around for a while?
• Is it useful enough to have been packaged in many places?