Yes, definitely! 😊 Simply tap the category heading and speak your item while the mic shows on screen.

If you do not wish to use voice input (we totally get it if you don’t), you can go to Settings – Categories – Input mode for click on category. You can then select “Manually”, if you wish to add your items by typing them. 
If you choose “Nothing”, then tapping the name of the category does not prompt any action.

If, by any chance, your item already exists on the list, you will get a short on-screen notification.