This feature request is working its way through the backlog queue. No new details are available yet.
-WarrenKrsto Savic commented
Currently there is only possibility to add SharePoint document libraries as tabs. Consider adding sharepoint wiki pages, lists and calendars as tabs.
Due to a priority shift we need to move this one onto the backlog again.
I’ll keep you posted once we can pick up the forward momentum again.
This is in internal testing. I don’t have exact timing for you, but wanted to let you know it is coming!