To change the comment icon so that it would display a New Comment! notification every time somebody writes a new comment on an invoice (e.g. the comment icon could be flagged, displayed in another colour or with an exclamation mark, etc.; in fact any visual means which would distinguish the invoice from hundreds of other invoices in our inboxes could work). The notification should disappear when somebody reads the comment.

Now we only get notifications when somebody mentions us using @ in the comments section, but this function is rarely used. Moreover, there is no possibility to filter invoices based on whether they have comments or not so there is no good way to spot those invoices which require our immediate actions.