Some of these already exist. “Nearer” has existed several times. The problem is one of users. The odds of there being someone using the same service in the same club, bar, grocery store, coffee shop are so small none of those services has ever worked.
As for “NoPeek” unfortunately no one wants that. You can make the service. No one will use it. Check out the Startup podcast, Profiled, about a dating service that tried it. (I hope that’s the correct episode)