SheerSEO - SheerSEO helps you to track Google Search Engine Rankings for critical keywords. PageRank, Back Links and more.
Keyword Discovery - Keyword Discovery is a keyword research and analysis tool.
GrepWords - Grepwords is an API-first Google Keyword Suggestion Tool.
iSpionage - AdWords competitor keywords with the click of a button and monitor competitor PPC landing pages.
KeywordTool.io - KeywordTool.io is the best FREE alternative to Google Keyword Planner and Ubersuggest. It uses Google's autocomplete feature to get over 750+ long-tail keywords for any given query.
Keyword Country - Keyword Country is an AI-powered keyword research tool.