It’s been around for many years now and famously was used in the consultations for the constitution of Iceland. We also used it in Bulgaria back in 2013 and had a community of more than 3000 users, but it lost traction due to being ignored by politicians and controversial debates.

You can see more recent activity on https://www.citizens.is/ , particularly the impact and news sections.

There’s https://codeberg.org/flohmarkt/flohmarkt for a marketplace.

I’m really missing something like https://yrpri.org/domain/3