Personal Genius is great for getting into the flow state for writing.
New Behavior Generator for pulling on the behaviors of a writer.
Prosperty, too.
But the best is PhotoReading. I remember a mystery writer who had been sending chapters to his agent after four, five, or six drafts. When he learned PhotoReading, he PhotoRead mystery books before writing, and soon he was submitting chapters to his agent after one or two drafts. It significantly improved his writing.
We also had a romance novelist who wrote under several names. She said PhotoReading kept your creative juices flowing.