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.
Review Scraper API - Reviews from 50+ sites in JSON
Keyword Surfer - Get search volumes & keyword data directly in Google.
Product Reviews - Concise and unbiased software product reviews
Keyword Explorer by Moz - Find the best keywords to improve your website's SEO traffic
Typical Contents - Wirecutter for clothes