Condefinition reads incoming roll templates and looks for imposed conditions and saving throws. It display a button(s) in chat that allow you to quickly apply a corresponding token marker, define the condition, track concentration, roll saving throws and/or apply damage from spells or effects that are triggered by saving throws.
You can find documentation here: https://app.roll20.net/forum/post/12380850/condefintion-1-dot-0-now-user-configurable, on the Roll20 Forum.
The documentation has a link for the code, and the script itself should be available shortly from the Roll20 One-Click Repo.
