Sounds very similar to the old webOS app, BlockChalk: https://techcrunch.com/2010/01/08/blockchalk-location/ https://techcrunch.com/2010/01/08/blockchalk-locat

Sounds very similar to the old webOS app, BlockChalk: https://techcrunch.com/2010/01/08/blockchalk-location/ https://techcrunch.com/2010/01/08/blockchalk-location/ It dynamically created a message board for geolocations and anyone was free to post to it. It got a bit out of hand with spam and cyber-graffiti... Looks like the service is long gone (some random housecleaning blog is on the domain now). A big limitation to the app's usability was you had to be within a certain distance of a location to access the "chalk" for it. It sounds like a cool service to try out, just not an iOS user...