Haark - Tracks your sites and notifies you if they're down
Troops Slack Sales Gong - The most customizable Salesforce Gong in Slack
Rollie - Know where your money goes. Spending tracker for iPhone.
Hyperping - Cheap uptime and performance monitoring with detailed reporting and flexible alerting
CostTeam - Identify online subscriptions and other recurring expenses.
UXPin + Slack - Keep tabs on design projects in Slack