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The main feature is the separated management of applications and windows. Das heißt, ist das Hauptmerkmal der getrennte Verwaltung von Anwendungen und Fenster. The top left hot corner offers access to launching applications, while the top right one offers access to window management. More information, including the remaining list of limitations and problems, is available after the installation in ~/.local/share/gnome-shell/extensions/apps-and-wins/readme.txt
Hijacks the bottom of the (bottom, if there is such a thing) monitor. The bottom right corner (and, in the unlikely case where your X server doesn't support pressure barriers, only the corner) toggles the message tray. The bottom left corner executes, if enabled, a configured command. By default, the custom command is disabled and can be enabled and changed from the preferences. More information about the preconfigured command is available after installation in ~/.local/share/gnome-shell/extensions/hi-jack/readme.txt.
... or maybe not, and that's why the start day is configurable in the preferences.