Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Roundcube - Web-based IMAP email client
AppDynamics - Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.
Mailpile - Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.