Find the icon pack version history with respective download links and whatnot here.

Guides:

Anime Folder Icons Full Pack: 

Latest version (updated 10/23/2016): http://go.sei.moe/2ex6Mvt 

Previous versions:
07/08/2016: http://bit.ly/29hVplV
05/01/2016: http://bit.ly/1mXoSGe

Anime Folder Icon Packs per Season:

[Latest upload] Spring 2017

Previous seasons: