John used a DigiTech Whammy 4 Pitch Shifter very briefly during the latter part of the Stadium Arcadium tour around 2007, most notably during the band’s performance at Coachella. For more details or insights, check the comments section below!
John Frusciante’s DigiTech Whammy 4 Pitch Shifter
He used this pedal in the intro of 2007 Coachella.
https://www.youtube.com/watch?v=U3sC-Z0CbNg
Here you can hear him using the Whammy starting at 0:25 sek.
This is the Jam from Empire Polo Grounds, Indio, CA, USA – 2007-04-28, so Coachella I guess