It's different for each sheet, so it's kind of hard to say. Also, some animations are designed for flexibility-- for example, multiple animations in a row could be used together for a longer effect, or used individually.
I might write up some sort of guide eventually. Good idea!
It is kind of hard to just drop and use these into a MV project. How do I set them up in the editor? I added a sheet and told it to do 15 frames (the fire one)for example, and no animation shows up when I click Play in the Animation area. Do I have to do something different to get it to work? There was no .json file either.