We switched to Nightwatch from Stat after some issues and realizing they support wide range of functionalities with have a more friendly interface. Happy so far!
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
OnCrawl - OnCrawl is a SEO crawler and log analyzer that helps you improve your SEO performance. Increase traffic, rankings & revenues. Start your 14-day free trial.
Serpstat - Search analytics, Rank tracking, Backlink analysis and Site Audit tool.
SEO Analyzer By Neil Patel - A free SEO analyzer for your site
SEO Tools Centre - SEO Tools Centre provides SEO checker services for websites.