(SOLVED) What are Gnome shell extensions exactly

I am a little confused as to what Gnome shell extensions actually are:

I can see Gnome Shell integration when I click on jigsaw shaped Add Ons Manager app extension in Firefox, but I never see it doing anything.

I can get more when I run Gnome tweak tool.


What are they exactly? - Something for the OS or Browsers?


More importantly, as you have to install them before you know what you get, which ones seem particularly useful to have installed?


How do you know if they are running OK - I sometimes get notifications suggesting that they have not loaded - or something similar - yet everything seems to work OK.

Hi Gnome Shell extensions are useful utilities that you can add to your system. I have weather applet (Never got the default Zorin one to work correctly - and when I did get it to work it picks up Manchester Airport. I use the Weather Underground extension - have to register by email for API but it works), Gno-Menu - brings full Win10 look in respect of menu - text and Icons, Text Scaler which sits in the sytem Tray with a simple slider to make all text scale upwards instantly - saves numeric input in Tweak Tool, word clock (on an old version of SuSE it would be the same as 'fuzzy clock', well similar), show desktop, Shift, Caps, Numlock indicators, Random Wallpaper applet, Extensions Applet - switch on/off the ones you want/don't want from the panel instead of launching Tweak Tool. If some won't work it is because they were designed for an earlier release of Gnome Shell. The Jigsaw in Firefox is the Chrome extension to allow the website to integrate with your Tweak Tool to allow installation of the Extensions.

Thanks, Swarf - much clearer now.

Just to add, once you get the browser extension installed it also makes updating of extensions easier. When you boot up you may get a notification popup saying there is an update for a certain extension - click on the notice and the browser should open to the extension web page - you will see a green square with cog in it - this is what you click to apply the update - think it launches the 'install' box once more for you to click on to update the extension.