Does your product idea have market fit? Will you have buyers? Don't know what to make/sell?
hustleos.com - a guide about how to go from idea → validation → mvp → success. Includes many resources, tools, advice. It turns this big scary adventure into more manageable and linear step by step instructions. Very cool!
keywordtool.io - Check Google/Bing/Amazon/Instagram/Youtube/eBay/PlayStore for frequency of keywords searched. Amazing resource to search multiple platforms in one place!