I deal with a lot of different clients on a daily basis. It is a bit of a chore to figure out how to tie together their different messaging apps in order to interact with them and be alerted of any needs or emergencies.
Most clients nowadays use either Slack, HipChat, Google Hangouts, and Skype. With Slack and HipChat being most popular in my regards. The main issue I have is that I use Linux and the Slack web interface is a resource hog and can only monitor one client at a time. Whichever one is loaded at the time. The HipChat web interface is a bit lighter but the same issue persists as with Slack.
Luckily with Slack you can enable either (or both) XMPP and IRC. With HipChat you can only enable XMPP.
For Slack you go to Admin Settings and enable both or your choice:
Then go to your Account Settings > Gateways to see your connect info and the unique password for connecting to the gateway as yourself:
Now you can take that info and use it in your favorite IRC/XMPP client. For me I use either IRSSI (for IRC) or Profanity (for XMPP). Both work in a similar fashion so there is not much learning curve if already know IRSSI. You can add multiple accounts in both so you can have coverage on all clients. Refer to the IRSSI Docs or Profanity Docs for detailed setup info!
But what about on my phone!?
With my clients I need to be available in case of an emergency of if I am at a meeting with another client. So having mobile access to my various accounts is needed. I currently have an iPhone so I use ChatSecure for XMPP and Mutter for IRC.
Now I have the ability to add numerous clients via IRC/XMPP t connect to their Slack or HipChat with only occasional weirdness in compatibility and only seeing some emojis as :name: instead of image. But small price to pay for usability and lightweight interaction.