AffiliateWP - A powerful affiliate marketing solution for WordPress.
Google Trends - Explore Google trending search topics with Google Trends.
ReferralMagic - Turn your users and customers into referral magnets.
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.
Everflow - Partner Marketing Platform - Track, Analyze & Automate
Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition