[laulis]

There's Flaschenpost[1] in some cities, and afaik it's pretty popular. Me and my partner use it pretty regularly.

[1] https://www.flaschenpost.de/

[dark-star]

wow, what a badly designed site. I can't even look at it because it keeps pestering me with some popup that asks for my ZIP code (which I don't want to provide, as I just want to know what that page is all about)