To change MoneyWiz icon, please go to MoneyWiz Settings -> General -> MoneyWiz Icon. You'll see a collection of currently available graphics (including a retro icon from MoneyWiz 1!). We plan to extend this collection as new icons become available.
To change the icon, simply tap on it. To see how your new icon looks like on your Homescreen, just go close the application.
Please note that it is not possible to upload custom-made icons.