Airmiles galore!
ARTS & CULTURE
It started out as a hobby and ended up being a global service: I am referring to the service offered by flightradar24.com that helps commoners around the world keep a track of the entire air traffic around the world. 'Entire' is not exactly true as military and other sensitive flight details are obviously blocked / not tracked. Even then, it is a very useful and educative service!
On June 30 2018, the flightradar24's twitter handle showed a visualization around their observation of that day being the busiest till date. That visualization was just awesome!
https://twitter.com/flightradar24/status/1013088775973556224
For those interested in trivia or having aviation as their core interest area, given below is a link to their website which explains how the flights are tracked.