OnlineOrNot - Uptime monitoring for software teams (even teams of one).
SEMRush - All-in-one Marketing Toolkit for digital marketing professionals.
Statsignal - Statsignal is a simple and cost-effective way to monitor your website or server and publish a status page of your system.
Sitechecker - All-in-one SEO platform including rank tracker, website SEO audit tool and website changes monitoring. Detailed reports by 100+ parameters with how-to-fix guides.
Uptime Kuma - A fancy self-hosted monitoring tool.
SEO Site Checkup - Find comprehensive search engine optimization (SEO) tools for your site.