Statsbot - Connect your database, let Statsbot generate data relationships from your database automatically, and get your first insights in a matter of minutes.
WebGazer - Monitor your website's availability with WebGazer, review its performance and get instant notifications when your website goes down. No installation required and free plan available.
Baremetrics for Slack - Subscription analytics, insights & notifications in Slack
Oh Dear! - Website monitoring, without the hassle
Mode for Slack - Share dashboards and analysis with your team on Slack
updown.io - updown.io is a HTTP(S)/TCP/ICMP monitoring service which checks periodically the URL you want and reports back any anomaly.