Why don't you run into friends in the city anymore?
Quick answer
Parages brings back chance encounters by pinging you when a friend you added is nearby in the city, with the proximity check running locally on your phone.
Cities are dense with people you know and somehow you still never bump into them. You shop the same streets, ride the same lines, and miss each other by a block and ten minutes. Parages brings back the happy accident. Add your friends, go about your day, and when one of them is truly close, your phone lets you know. The spontaneous run-in returns, on purpose this time.
In one sentence
Parages pings you when you pass near a friend. It tracks nobody.