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.
coconutBattery - With coconutBattery you are always aware of your current battery health. It shows you live information about the battery in your Mac and iOS devices (iPhone, iPad)
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Accubattery - Monitor's battery capacity through the use of science
Better Uptime - We call you when your website goes down
GSam Battery Monitor - Monitor your android devices battery usage.