Baremetrics Benchmarks - Benchmark your SaaS metrics with other startups
Analytics Pack - A curated directory of the best startup metrics
Open Benchmarks - Live SaaS metric benchmarks from over 600 companies
ChartMogul API - SaaS metrics and analytics for any billing platform
MRR.io - Monthly Recurring Revenue (MRR), Churn, Lifetime Value (LTV) - SaaS metrics for your business
Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded