Other extensions give a GNOME 2 feel to the GNOME shell. Frippery Applications Menu replaces "Activities" in the top shell bar with an applications menu. When Frippery Panel Favorites is installed, the top bar includes icons for the applications that have been added to the Dash as favourites. Frippery Bottom Panel adds a window bar to the bottom edge of the screen, reminiscent of GNOME 2 and Windows 95. But the bar's design doesn't look quite right in GNOME 3 – it seems a little out of place; also, after this extension is installed, some keyboard shortcuts don't work the way they should in GNOME 3.
Places Status Indicator adds a panel entry that has a function similar to GNOME 2's Places menu. Users who don't like the way Alt+Tab cycles through windows on multiple workspaces may want to look at AlternateTab or Windows Alt Tab, which limit the function to the workspace that is currently being used; GNOME 3.2 actually offers similar functionality via Alt+Esc. NetMonitor Lite displays the network bandwidth in the top shell bar. System Monitor, meanwhile, displays system utilisation graphs in the bottom status bar.
Some extensions add functionality that GNOME 2 didn't have. Unit Converter, for example, uses GNU Units to convert distances in miles to kilometres. Journal adds an overview of data tracked by Zeitgeist to the GNOME shell.
For many extensions, the web site does not provide any information on how to use or configure them. For Area Screenshot, for example, you need to consult the readme file on GitHub to find out how to configure the extension to take a screenshot from a certain part of the screen.
And the information about whether an extension is even compatible with a specific version of GNOME doesn't always provide the whole picture. When this article was started, the web site only offered a version of Dock, recently praised by Linus Torvalds, that required GNOME 3.3.2, even though the extension was certainly available for GNOME 3.2 at that time, as well. A week or two later, the web site offered a version that was compatible with GNOME 3.2.
Some distributors offer the Dock and other extensions in their repositories, from which they can be easily installed for the whole system; each user then has to individually activate them using the GNOME Tweak Tool. With this type of installation, all of the required dependencies are installed – according to some user comments, this is not the case when using the web site.
Distributors also provide updated extensions in their update repositories, while the GNOME Shell and extensions web site do not yet provide an update function. The web site recommends uninstalling extensions via the "Installed extensions" page and then reinstalling. Because of errors, however, the GNOME 3.2 mechanism for uninstalling does not work. There are patches to fix these bugs, but the web site says that only Mageia has included them in its GNOME packages so far; nevertheless, uninstalling worked most of the time in Fedora 16. If uninstalling fails, users have to manually delete the extension from ~/.local/share/ gnome-shell/extensions/ and restart the shell by pressing Alt+F2 and then entering "r" in the resulting dialog.
The developers running the site have said that they test all extensions for malware before adding them to the web site. Just as with Firefox extensions, quality is variable. Some well-known extensions have not yet been added to the web site, such as GNOME Shell Extension Weather, which adds a small temperature and weather display next to the clock in the top shell bar. Some of the extensions that were part of the excitement for the most recent Linux Mint are also missing.
Overall, the web site and support for it in the GNOME Shell are still suffering from a number of teething problems. Nevertheless, the site certainly has potential and could very well soon become the go-to place for GNOME extensions.