Seems like they cost money on Google. Are they free on F-Droid?

Edit: It seems like they are, but without the word "Pro" in the title. I can't figure out what makes any of them "Pro".

Edit 2: Nope, some of them say "Pro" on F-Droid, too. I guess it's just in the name. Weird.

Some functionality is missing in the Fdroid versions though. E.g. the calendar app is missing the comprehensive editing tools from the Google Play version. The solution? Installing the binaries right from their Github repo.

AFAIK There's no paid apps on F-Droid, so it's likely that they are free.

Why?

I'm guessing because of what's mentioned here: https://news.ycombinator.com/item?id=31491321

TLDR: Their Calendar app became "not free" and you needed to pay to get notifications or alerts, but only if you downloaded from the Play Store. It's still completely free on f-droid