Hexadecimal is described as '* Uptime monitoring - checks are performed approximately once every minute from one of the available locations worldwide. During downtimes, checks are performed from four different locations simultaneously. Downtime is only recorded if more than half of servers can confirm it' and is an app in the Network & Admin category. There are more than 100 alternatives to Hexadecimal for a variety of platforms, including Online / Web-based, SaaS, Windows, Linux and Mac. The best alternative is UptimeRobot, which is free. Other great apps like Hexadecimal are Pingdom (Paid), PHP Server Monitor (Free, Open Source), Freshping (Free) and Cabot (Free, Open Source).
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.
Website/Server monitoring with fast notification via Web, SLACK or E-Mail on issues. What you get: 25 monitors, checked every 5 minutes. Now includes SSL-Certificate validation and port checks. Totally free!.