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.
AdRoll - AdRoll is a leader in retargeting display advertising. Draw the right people with the right strategies.
Google Trends - Explore Google trending search topics with Google Trends.
Marin Software - Optimize your Search, Social & Display ads across channels and devices. Marin Software, the leading cross-channel performance advertising platform.
Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition
Google Marketing Platform - Google's unified and improved marketing and analytics tools.