Back when Firefox 4.0 rolled out in March one of the (many) new features was a little something called App Tabs. This was something borrowed from Chrome and even we didn’t really understand the correct use of this feature when we wrote about it in the Firefox 4 Quick Guide. Of course at this point, it really doesn’t matter what you are using an App Tab for as their behavior won’t change until Firefox 9 is released in December. As reported earlier, in Firefox 9 the new ‘Don’t Load Tabs’ option is going to exclude App Tabs starting in Firefox 9.However, if you don’t plan on using the new ‘Don’t Load Tabs’ feature, ti shouldn’t really matter still what type of sites you use in your App Tabs.

So, what are AppTabs and their correct use? From Firefox Help: What are App Tabs?

App Tabs allow you to always keep your favorite web apps like Facebook, Gmail and Twitter open and just a click away. App Tabs are small, can’t be closed accidentally and open automatically when you start Firefox.

• App Tabs are small – only showing the site’s icon, not its title – and they live on the left side of the Tab Strip.
• App Tabs don’t have a close button so you can’t accidentally close them.
  • You can still close them by right-clicking on them and selecting Close Tab from the menu.
• App Tabs notify you with a blue highlight when they change.
  • If you have Gmail set as an App Tab, for example, and you are using a different tab when a new email is received, your Gmail tab will glow.
• All of the App Tabs you have set when you close Firefox will open as App Tabs when you start Firefox again.
• Links to other websites open in a new tab so that your App Tab doesn’t change.
  • Many web apps, like Facebook, already do this but an App Tab will make this happen even when the website isn’t set to do it.

We have setup a poll about App Tabs on our Facebook page, please take a moment to participate.