Stalker app
...is the judgement from the person who A. has no friends B. no one considers them a friend
Pick one
Some people like each other and want to connect as conveniently as possible, perhaps share personal information with each other. Perhaps they have a lot of trust not to be judged or mistreated based on allowing others to know them more.
You judge that it is a stalker app, okay. I wonder if you are one of those safe, trustworthy, fun, kind, nonjudgmental people, or those other kind of people.