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.
Muzli - UI/UX and Design Inspiration Chrome Extension
Google Trends - Explore Google trending search topics with Google Trends.
UI Garage - Specific mobile and web design patterns for your inspiration
Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition
Design Hunt - Curated design inspiration for everyone