Keyword Surfer is a free extension that allows you to see search volumes directly in Google search results
Bulk Keyword Tool | Keyword Sheeter
Answer The Public - Search Volume for AnswerThePublic
QuestionDB is a tool that lets you search a massive collection of user questions to get original ideas for new content.
Keyword Research and Analysis Tool SEO With Data Driven
Domain Research Spot| Keyword Reseach SEO PPC opportunities and outsmart your competitors
Google SERP Checker | Free Online Tool | Location Specific