Wait a minute. Are you saying there is an app which provides information about the racial makeup of neighborhoods?
This is one of the biggest business opportunities in America. Everyone votes with their wallet, and they vote to spend their biggest dime on where they live: away from minorities.
This is the biggest open secret in America. It's also the largest industry in America, Real Estate is a $1.6 Trillion business, and that's just the actual RE value itself. This counts for the effort to gentrify an urban center for a Trump Tower, all the way to plowing down an entire mountain in California for a McMansion subdivision for self-professed Liberals. Because we all know how Liberal it is to move your kids as far away as possible from black people.
But, demographic information is taboo for RE Brokers due to the Fair Housing Act and other similar legislation. It's an insta-license pull for any Broker that is even suspected, in any tiny way, of providing demographic (racial) information to home buyers. This extends right down the chain to Zwillow and any other RE database. It's pretty risky for RE sites to even link rather innocuous external websites like city-data. And you'll notice city-data doesn't granularize down to a useful way about each individual neighborhood. You have to get even more wily, and find sites which give demographic data about each school district or high school, if you can find it.
So if Nextdoor has found a way around this, it would be quite literally a 100-billions per year business.
Ideally, there should be an app which gives you instant racial demographic data per address, because as everyone knows (and we know they know it by how they vote, with their wallets, on their most expensive purchase), you want to live in a White neighborhood.
The biggest open secret in the USA. I have long, long waited for this issue to be addressed. But it's not going to be addressed because 'White Flight' is very literally the largest business in the US (even larger than petrochemicals, automobiles, or technology), and moving Minorities around is the best way to turn a piece of wasteland shithole in Southern California into the second season of True Detective. RE development baby, the last Pork Barrel.