Friends with GPS Benefits
I can't live near friends right now, but I can synthesize some propinquity.
iOS's Find My enables friends/family to track my location in real-time. As somebody who hates notifications and SMS, this tech is godsend. My wife knows which coffee shop I'm at, my friends know exactly how much traffic I'm stuck in, etc.
I sacrifice my own privacy for convenience, but I never expect others to do the same. All my friends/family should feel entitled to privacy. There is no shame in unrequited location sharing.
Unlike read receipts, I do not expect the social norms on location-tracking to change any time soon. Most of the benefits of live location are conferred to the sharer rather than the receiver.
I don't want to bother people whenever I fly from SEA to SFO/LAX/etc. I want friends to know when I land, and I want friends to join my festivities.
You cannot count on others to check your location, nor to be available for your flights/fancies. Deeper relationships demand effort/planning/coordination. This isn't a replacement for real plans -- it's a backup for happy accidents.
Luckily, Find My can also notify them when you're near their 'hood.
This tech becomes extra valuable as you accumulate friends across Earth. You'll find that it's the biggest small world after all, filled with familiar faces in far-away places.
Don't leave serendipity to chance.