statuspage - A simple self-hosted status page site with an API written in Django under the BSD license.
HelpStack - Open Source mobile help framework to support iOS and Android app users.
UptimeRobot - Free Website Uptime Monitoring
Helpshift - Helpshift is an in-game customer support platform that enables mobile apps to improve customer experience, drive higher ratings and increase retention.
StatusPage.io - StatusPage.io is the best way for web infrastructure, developer API, and SaaS companies to get set up with their very own status page in minutes. Integrate public metrics and allow your customers to subscribe to be updated automatically.
KeyReply - Omnichannel keyboard for mobile teams to respond better and faster.