HetrixTools is described as '=== Free Uptime Monitoring ===' and is an app in the Network & Admin category. There are more than 50 alternatives to HetrixTools for a variety of platforms, including Online / Web-based, SaaS, Self-Hosted solutions, Android and iPhone. The best alternative is UptimeRobot, which is free. Other great apps like HetrixTools are Pingdom (Paid), PHP Server Monitor (Free, Open Source), StatusCake (Freemium) and WebSite-Watcher (Paid).
Dashboard with 50 Monitors, Checked Every 5 Minutes, Totally Free. Monitor HTTP(S), Ping, Port and check Keywords. Get alerted via e-mail, SMS, Twitter, web-hooks or push. View uptime, downtime and response times.
Pingdom web site monitoring and other infrastructure for you and instantly let you know when anything goes wrong. Measure uptime, downtime, and the performance of your website as experienced by visitors.
PHP Server Monitor is a script that checks whether your websites and servers are up and running. It comes with a web based user interface where you can manage your services and websites, and you can manage users for each server with a mobile number and email address.
StatusCake.com is a free website monitoring tool which allows users to track up to 10 websites and get alerted when their site is down or is having trouble. Downtime root cause analysis is included in the free plan to help users diagnose and fix issues.
All of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool. Input a domain name or IP Address or Host Name. Links in the results will guide you to other relevant tools and information.
Pingbreak is an original and free monitoring service. Get notified through Twitter if your website is down. Pingbreak checks all of your websites each minute and alert you instantly by Direct Message (DM).