If you want to get in touch with one or more colleagues just use the built-in Workfeed chat. It's located in the top right corner of your home screen.
Once you've clicked on the chat-icon you officially entered the chat. Here you can either start a new chat or use the team chat with every colleague in it, or you can access your old conversations.
When starting a new chat you have two options. Do you want it to be a group chat or an individual conversation?
In case you decide to create a group chat just tick off the people you want to be a part of the group. You'll also be able to give the group a name of your choice.
When you're inside the chat it's pretty straightforward. In case you want to send files just hit the attachment icon next to the text field.
If you want to see if somebody has seen your message just click on the message itself. The same goes if you want to copy a message.
FAQ
Can I send images or videos?
Yes, you can. Just hit the attachment icon next to the chat.
Can I turn off notifications to the chat messages?
At the moment you can only deactivate all chat notifications. You do this from your homepage where you can click on "settings" under your profile picture. From here you can manage all your notifications.
Can I see who read my message?
Yes, just click the message.