macOS Console - An application to view live log files.
Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
BareTail - BareTail is a real-time log file monitoring tool. Features Real-time file viewing
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Goldilogs - Intuitive and powerful real-time log viewer. Low CPU/RAM/network usage. Handles large files (gigabytes), instant loading, colour highlighting, tailing and powerful text/RegEx searching.
Better Uptime - We call you when your website goes down