LeadDelta - LeadDelta will help you to grow, manage, and engage your Linkedin connections. Cut through the noise and create new opportunities in your network.

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.

Entro - The holy grail of email introductions

Platypus - Realtime server monitoring and reporting

TreeLine - TreeLine just stores almost any kind of information.

Nagios - Complete monitoring and alerting for servers, switches, applications, and services