Keyword Surfer - Get search volumes & keyword data directly in Google.

TubeBuddy - The Premier YouTube Channel Management and Optimization Toolkit

Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition

DemandSphere - DemandSphere is an advanced-level software that helps marketers to create the best digital appearances of their brands.

Keyword Tool & Content Assistant - Content optimization tool to boost your rankings

VidIQ - Generate tags for YouTueb Videos. Works as a browser extension .