This is nice. What happens when I'm in within 0.5km from someone and from someone else, but these two other people are not within reach of each other?
The message will be delivered only to people within 0.5km. But you can still message anyone by @mentioning their handle even-though they are not near you.
Did I answer your question?
I really like this feature! Whats your vision?
The idea sparked when I went to a tech conference of 1500 attendees and there was no way to chat with the attendees.