A collection of fun parkrun web apps below:
https://touristtool.mybluemix.net/
Find your nearest parkrun
http://www.challenge-chaser.com/map
A map that shows locations that would meet various challenges
https://wiki.parkrun.com/index.php/Club_Membership_(5km)_Totals
The number of people that have completed x number of runs
https://chrome.google.com/webstore/detail/running-challenges/kdapmdimgdebpgolimjnmcdlkbkddoif?hl=en
A Chrome extension that can be added to add extra detail to you parkrun results