Mapbox and Skyhook have teamed up to map the incredible number of wifi connections made by smart phones around the world. If you want to draw your own map, you can use this the world map pdf of World vector maps free. The World's Wifi map allows you to explore millions of wifi connections made in cities around the world.
The yellow dots on the World Wifi Map show wifi connections made in the last six months. The blue dots date back to 2013. The map includes quick links to zoom in on a number of different cities. If you zoom out on the map you can see that each city map also allows you to explore quite a large area around the selected city.
Plotting so much data on one map is made possible by Tippecanoe, which can make vector tilesets from large amounts of data. You can read more about the Skyhook data plotted on the map and how the map was made on the Mapbox Blog. Source