I read an article about ichigo ichie, an idea from the Japanese tea ceremony. Roughly: even if the same people meet again in the same room next week, it won't be the same gathering, because everyone will be slightly different. So treat the one you're in as the only one you get.
The research it cites is pretty limited, but it points the same direction. People report better days when they've had more small talk with acquaintances. Coffee shop customers who spent thirty seconds actually talking to the barista came away happier than the ones who kept it quick. And students who were told to imagine graduation was close paid more attention to the life they already had. Nothing changed except how much time they thought was left.
The awkward part
The article is basically telling you to put your phone down. So building an app out of it is a little ridiculous, and I had to decide what would make it not ridiculous.
Two rules. You never open it while you're with someone. And it never treats a person as a record you're supposed to keep up with.
That second one rules out the version I'd probably have built by default: a lightweight CRM for your personal life. Log people, set follow-up reminders, get nudged when you haven't talked to someone in a while. It's the obvious product and it gets the idea exactly backwards. The article says outright that none of these conversations has to go anywhere. Once you're tracking last-contacted dates you're running a pipeline.