Full Detail of the Productivity Statistics hosted by biz_classic: https://classicdelegate.biz/productivity
This new features is possible thanks to the blockchain plugin of delegate alessio: https://github.com/alessiodf/productivity-statistics
There is also another quick and dirty frontend for the plugin by delegate civseed: https://ark.party/visualize/productivity
It might be a small feature but it shows well how the plugin system of Ark can be used to extend the core blockchain with custom functionality.