AdWords Keyword Generator - Instantly generate thousands of targeted longtail keywords
Keyword Discovery - Keyword Discovery is a keyword research and analysis tool.
PPC Gear - Instantly find where you lose money in Google Ads
GrepWords - Grepwords is an API-first Google Keyword Suggestion Tool.
Keyword Surfer - Get search volumes & keyword data directly in Google.
iSpionage - AdWords competitor keywords with the click of a button and monitor competitor PPC landing pages.