Opsgenie by Atlassian is a cloud-based incident management platform for operating always-on services. It provides reliable alerts, on-call schedule management, and escalations. In terms of standout features, it has a quiet hours feature that lets you disable alerts, as well as a heartbeats feature that generates notifications if scheduled jobs don't check in within the allotted timeframe. OpsGenie has a friendly UI that's easy to use, as well as competitive pricing.