I once played on a server that had the top players in all kinds of catagories scroll by in the bottom left part of the screen like who had the most kills how had the longest range shot and so on does anyone know what plugin that is ?

its player ranks. I'm not allowed to link it, but with a bit of google work, you will find it ^^ It has something to do with "stones" and "music" 

player challenges? https://umod.org/plugins/player-challenges

search google player ranks