If your system is set up so apps show up in catalog.nsf, then just find them by title, click the actual document row, and hit the 'open' view action. This opens the app and puts it on your workspace.
To move them to different tabs, just drag them to the tab.
The workspace is pretty much identical to the iPhone/Andorid concept only 30 years old...Notes been doin' the app thang for a long time!