Yes you can, but this is a Pro feature! When you are a Pro user you will be able to have your own company logo instead of the SpinOffice logo. Go to Administration -> CRM preferences -> Company and click on ‘Browse’ to add your logo from any local disk. Click on the save button to confirm, and you’re done! It appears in the left corner on top.
When you have added your company logo during your limited trial, it will automatically be displayed once you have become a Pro user.