Modifying Popularity Contest plugin to work with post Tags instead of Categories

I really like this plugin but am finding it would be much more useful if there were a short code I could insert that would give me a list of the most popular posts that are under a common Tag opposed to Categories.
I want to be able to have a list that populates when you click on any tag. I tried to duplicate the akpc_show_top_ranked_in_cat code to work with tags instead though I am a bit of a novice and it always comes back with “(none)” in the loop.

I understand this might be a question that would require quite a bit of recoding to answer but please if you could, let me know just how hard you think it might be and if possible at all.

Thanks so much!