The Landing Page Cookbook - A guide for makers who want to create better landing pages.
Website Speed Ranker - Compare how fast your website loads vs your competitors
Landing Pages in MailChimp - Easy to build, custom landing pages for free
Textalyzer - Analyze text readability and SEO parameters
SaaS Pages - 900+ Screenshots of the best SaaS landing pages
SanityCheck - Get the exact data you need from Google Search Console.