Ziflow allows you to brand your account. If you are an account owner or administrator, you can upload your company logo to the dashboard, sign-in screen, e-mails, and Proof Viewer.
To do this, click on your profile avatar in the top right corner and select Settings. This will take you to the Branding menu.
Depending on your Ziflow edition there will be different branding options available. Read more about branding in Ziflow.