GrowthHackList - 100+ curated growth hacks for makers + early stage startups
Viable Fit - Measure and improve your product market fit
Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
OpinionX - Stack rank people's priorities in minutes with OpinionX's free ranking surveys.
Ryan Holiday - We Invest $500k in Sci-Fi Founders.
Product Fit - Measure product/market fit in app with your users.