Slack is only available for Advanced users.
Shift supports the web application version of Slack.
This means there are some inherent differences in functionality between the Slack web app and the Slack desktop app.
The desktop app supports screen sharing, video calling, and voice calling, as well as many other conferencing features.
Currently, the web application version of Shift does not support screen sharing in conferencing, but it does support video calling and voice calling.
As soon as the Slack web app supports screen sharing, we will surely integrate that version into Shift as well.