Grindr is a gay sex app.
It is used to facilitate quick, on the spot sexual encounters between gay men.
I think a lot of straights are still in the dark as to the level of promiscuity that gay males still engage in. Delta and Monkeypox shed a little light on it where we all learned about the massive orgies that are quite common in the gay male lifestyle.
An average gay man today has a "bodycount" of different sexual partners that would've put the dudes in Van Halen or Motley Crue to shame during their heyday.