Filesystem:/private/var/mobile/Library/Preferences/com.apple.purplebuddy.plist

What is it?
com.apple.purplebuddy.plist represents a property list file holding the settings for the Setup.app as well as Springboard on iOS. The file is present on all iOS devices and holds the progress of the Setup so that the phone knows if you already selected a language, a country, a Wi-Fi Network, if you already signed into your iCloud ID and any other variable that might occur in Setup.app.

Where is it?
The position of the settings file is /var/mobile/Library/Preferences/com.apple.purplebuddy.plist

What happens if I remove it?
It might trigger the Setup.app again (this one will create the file again).