I run a television blog, where my contributors write reviews of respective series and grade each individual episode from A through F. I used the Advanced Custom Fields plugin to do that. I've been trying to find a plugin that would allow readers to rate each episode as well, but can't — especially for letter grades. I know I can probably buy a a theme that has it and change the look of that theme, but… that's a less than ideal situation. (I'm using a modified Twenty Ten theme… I know, so old!)
If there's anything you know of, or perhaps a way for me to build it (which I probably couldn't, given the average of all the ratings requires heavy work), I'd be most appreciative!
EDIT: Forgot to mention, ideally it could be excluded by category. The way I have my ratings built is the custom field only shows up if the post is marked in the "Recap" category, and then I use the post template plugin to have a different look for those posts, as well.