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.
CodePush - CodePush is a cloud service that enables Cordova and React Native developers to deploy mobile app updates directly to their users' devices.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.
Better Uptime - We call you when your website goes down
replit - Code, create, andlearn together. Use our free, collaborative, in-browser IDE to code in 50+ languages — without spending a second on setup.