TBExtInt is a Browser software developed by GS! Networks. After our trial and test, the software is proved to be official, secure and free. Here is the official description for TBExtInt:
BSEditor: Tired of having to download extensions and drag them into Thunderbird, then delete the original file? Want to install Thunderbird extensions quickly through Firefox? This is the extension for you!
Not available for Firefox 3.6.8.
TBExtInt allows you to install Thunderbird extensions via Firefox without having to save them to the desktop, and dragging into Thunderbird. With TBExtInt you can install the extension in One Click.