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 Surfer - Get search volumes & keyword data directly in Google.
Google Trends - Explore Google trending search topics with Google Trends.
KWFinder - KWFinder is a keyword research and analysis tool bringing hundreds of long tail keywords with low SEO difficulty. Try KWFinder for free!
Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition
DappRadar - A list of the best decentralised Ethereum applications