Vote or Subcategories
Vote Posts System, like rating stars
or how to understand the model good enough to create subcategories
For votes, you could think of them similar to Likes except that you'd also want to record the value of the vote (up or down) or for stars you'd record the number of stars. There are some gems you can look at for this as well: https://github.com/ryanto/acts_as_votable
I need to make a video on this soon!