A global, zoomable heatmap that lets you see where people are likely to gather at any given time in the future.
Events like festivals, concerts, protests, popular nightspots, beaches, busy streets, shopping centers, etc. would light up on the map. For any area, you could see the estimated number of people per square meter per hour in a selected timeframe.
People like to be around other people. This system lets anyone see where interesting places are.
Useful to marketers and salespeople to identify the hotspots and prepare campaigns around them.
Plan your vacation to coincide with the most interesting times in the area.
A google-maps-like platform overseen by reputable moderators/editors, similarly to how Wikipedia operates.
Future events and estimated number of people. The estimates have to be backed up by some data.
Busy streets at any given hour of the day, day of the week and time of year
Tourists attractions, vacation hotspots
Nightlife hotspots, promenades, clubs, restaurants, shopping centers
etc.
The moderators check the data and approve/reject submissions.
Anyone can point out wrong estimates and submit modification requests. This gets reviewed by the moderators before any changes are made.
I imagine spam could be a problem. People could try to submit inflated numbers to promote their business as more popular than it actually is.