Today the first of Feb is Global Switch day, Spread awareness of the Fediverse in your communities.
Don't link p.lemmy.world. it's well over a year out of date.
phtn.app probably looks a bit less suspicious, and also lets you use any Lemmy/Piefed instance.
You could say it as "phtn.app is a web portal for the fediverse" or something like that because the concept of web apps is confusing to many