A lot of my Slack integrations these days are powered by Zapier, but for regular dev work + client management, I use simple integrations like Trello, Github, etc. The life-changing part comes from being able to communicate and get updates from the multiple teams I work with in a given day, across multiple companies and groups, in one app that also works on all of my devices.

In my Slack team, I've also set up some private channels where I pipe in things like twitter alerts, flight alerts, etc. so that helps too!