Você pode ver as configurações de extensões / complementos do Firefox, como alternativa:
To uninstall iMesh and the iMesh Bar using the Windows Control Panel, please follow these steps:
Click on the Windows "Start" menu in the lower left-hand corner of your screen.
Click on "Settings" > "Control Panel" > "Add or Remove Programs".
Select "iMesh 5" and click the "Remove" button.
To uninstall iMesh Bar, repeat steps 1 to 3, selecting "iMesh Bar" and clicking the "Remove" button.
— iMesh FAQ