You will be redirected to the chrome web store, where an allthings pop-up will be visible. Here you can select the ‘Add to Chrome’ button in the top right hand corner.
Following this, a new pop-up will appear asking you to confirm the addition of the extension.
Selecting 'Add' will then result in the allthings web extension automatically being added to your chrome account. A small icon will appear at the top of your browser, which will indicate the number of updates to your lists.