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.
SECockpit - SECockpit is a keyword research and SEO management tool.
Keyword Surfer - Get search volumes & keyword data directly in Google.
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.
KWFinder - KWFinder is a keyword research and analysis tool bringing hundreds of long tail keywords with low SEO difficulty. Try KWFinder for free!
Keyword Eye - Keyword Eye is a suite of visual keyword and competitor research tools.