For those who prefer digital tools over reading long texts, the ACT Companion app (endorsed by Harris) guides you through the exercises. It puts the "PDF" content into an interactive format.
The strength here is the Defusion chapter. It is arguably the most practical section of the book. Harris provides exercises (like singing your negative thoughts to the tune of "Happy Birthday") that effectively strip the power away from harsh self-criticism. For those who prefer digital tools over reading