StatusOk (Open source) - Get notified through Slack/email when your website is down

Planable.io - Planable is the command center of social media campaigns trusted by agencies, freelancers, and marketing teams, that allows you to easily create, collaborate, get approval and schedule posts for your social media campaigns.

Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting

Revel - Revel Systems provides an iPad point of sale solution for restaurant and retail establishments.

Get Notified - Get Notified when something happens

Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.