The PPP Wikidata SPARQL tool used to be available at https://tools.wmflabs.org/ppp-sparql/, but the website is down at the moment.
There's a GitHub repository available, so it should be possible to revive the tool even if the authors have abandoned it.
Note: This task was part of the "Improving Visual SPARQL Query builders" project, carried out during the Wikimedia Hackathon 2019. Project poster: