From publisher blurb:
This book is designed to help narrator's, DM's and game designers who are happy with the lore of their games make suitable and fitting feats to fit within their games and be more closely personalised to the characters needs.
You can design and make a huge variety of feats using the drag and drop system that will work with advanced 5th edition products as well as basic 5e products.
The rules also allow for not just basic feats, but also transformational and synergy feats.
Transformational feats lets characters follow the story arc of being bitten by a vampire, or having a close encounter with a Mind Wasp and provides mechanical support. Sure, you can "just roleplay it" but here you can do the roleplay AND have mechanics to help you out!
User summary:
See also SRD: CPF