In the Netherlands we use Erbij, (https://erbij.app), which is now going international.
full disclosure, I'm one of the founders
We use datumprikker.nl, Facebook, WhatsApp and sometimes Signal or Meetup.com.
Not saying it’s not a good app, but your selling your book.
I'm not sure what your point is. Someone requested an alternative, an alternative was proffered and the personal interest disclosed.
This implies that this app is the established norm in the Netherlands, which it isn't (but the OP would like it to be).
It's great that people can post alternatives, but personal interests aren't what I took umbrage with.
>> In the Netherlands we use Erbij, (https://erbij.app), which is now going international.
This implies that there is nationwide traction for the app which there isn't. It has 300 reviews on the app store. That's called astroturfing (or, lying).