Statping is a free open source server monitoring application that includes a beautiful status page with charts for your end users. Monitor when your HTTP websites and receive notifications on many different third party services. You can also monitor your TCP/UDP services with advanced features for the tech-guru's. The Statping mobile app will connect to your server by scanning the QR code on the Settings page.

To see what Statping is, checkout the Github page!
https://github.com/hunterlong/statping

Statping has many amazing features that are completely open source.
- Monitor HTTP, TCP, UDP applications and services
- Receive Notifications on Slack, SMS, Email, Discord, Telegram, Webhooks, and Push Notifications.
- Run shell/bash command when a services is offline
- Create Messages for end users to view
- Real-time server Logs
- Add or Remove administrators and other users.
- Create Checkins for your services to send a curl make sure it's online
- Organize your Services with Groups
- View Response time and Failures based on time
- View up-to-date Github Issues
- Run on AWS, Docker, Mac, Linux, Windows, and even on the Raspberry Pi.

Statping is an awesome server that is developed in Go Language and is completely open source.