PingPing offers simple, fast website monitoring. It performs checks every 30 seconds and notifies users immediately if a site goes down or an SSL certificate is invalid. The service provides customizable status pages (multi-language, with performance graphs) for each monitored site. It is designed for solo founders and small teams. The site indicates over 15,000 websites are monitored with PingPing.
Phare Uptime
Phare Uptime monitors websites, servers, and APIs for uptime, offering alerts, incident tracking, and status pages.