TubeBuddy - The Premier YouTube Channel Management and Optimization Toolkit
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.
DemandSphere - DemandSphere is an advanced-level software that helps marketers to create the best digital appearances of their brands.
Google Trends - Explore Google trending search topics with Google Trends.
Searchmetrics Suite - SEO Software
Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition