I used an Apple IIgs back in high school, but mainly for running Apple IIe/c software. The only GSOS (aka Prodos 16) disk I had at the time only had the loader, not the finder or any other GS/OS apps. I recently dug around on the Internet and found both XGS32, an Apple IIGS emulator, and Apple's own freely downloadble GS/OS System 6.0.1.

The GS/OS includes a graphical user interface and Finder application that functions similarly to that of the Macintosh. The vertical line texture is caused by Apple's odd video mode implementation.

The GS/OS booting up. The icons in the lower left indicate optional extensions that have loaded.

Some bootable GS/OS disks do not have the finder or other accessories, and instead have the "Launcher", a lightweight way to start programs that use GS/OS. This seems to be used on many application disks that use GS/OS.

The basic layout of the GS/OS Finder is the same as MacOS. The Apple menu contains desktop accessories and a control panel, there is a single menu bar at the top of the screen, the drives are displayed as icons on the desktop at the right of the screen and there is a trash icon for deleting files.

The GS RAM disk has been turned on here just for show (not a good place to store your important documents!). The 5.25" drives are the same 140k drives used by the early Apple II and suffer from the same lack of disk insertion notification as IBM PC clones. Therefore an icon is displayed for each 5.25 drive present regardless if there is a disk in it or not.

File and program icons can be displayed on the desktop. The desktop is not actually a storage space though, the files icon is "displaced" from where it would normally appear and a "Put away" option in the file menu will return the icon to the files actual location. Trash seems to work in a similar way, storing icons until the Empty Trash option is selected or an application is launched.

An extra finder component lets you create aliases to files. In this case the file "Text Editor" is an alias for the Teach text editor application.

An interesting feature of the GS/OS finder is that it lets you change the color of monochrome icons and folders.
 

Several desktop accessories included with GS/OS 6.0.1 are a calculator, an on-screen keyboard, and a file finder.
 

The control panel (selected from the Apple menu) contains control panel items that modify the operation of GS/OS or the IIgs itself.

It seems they actually ported Wolf-3D to the IIgs. I could not get it to run under XGS32 though, but it was still interesting to poke through the files.

This is the "Teach" text editor that comes with GS/OS. It supports multiple fonts, sizes, and styles in the documents and runs inside the GS/OS GUI.

Finally, shutting down the Finder.