On The Job's icon can display a “play” badge when the timer is running (see preferences).
On The Job's timer can be controlled through the application's dock menu, as well as the menu bar status item.
Many of the columns in the job item list can be optionally hidden by right-clicking (or control-clicking) the column headers in the item list.
The “Duplicate” menu items in the Edit Menu can create a copy of entire clients, job folders, invoices, or job items.
Job Items can be dragged to be rearranged, or even dragged to other jobs. The item order is reflected in the invoices created from that job.
Settings of multiple items can be modified at once by selecting all of the items and changing values in the settings area. This also works for client settings (if, for example, you need to change your rate or tax information across all clients, just click on a client name, and choose “Select All” from the Edit menu).