You can find the Cover above the list of pages in the left side panel:
When you click on that item, your cover will show up in the editing workspace in the center of your screen. You can add information and preview in real time using the editing widget on the right.
To add a photo to the circle, click "Add Main Photo." Upload a photo from your desktop and choose if you want the frame to be a circle or a square.
Read more on the recommended dimensions for the main photo.
You can also set your background color or add an image as the background. Click "Edit Background" and select a color swatch, click the color picker icon to choose a custom color, or upload a photo.
If you choose a photo, our editor will do its best with whatever size you give it. It should ideally be at least 640 pixels across and 920 pixels tall.
Then, you can choose a font, and enter a name and date or subtitle for your Yapp. The background photos have a blur so that the titles and dates are readable.
If you want complete control over your cover, upload your own custom cover by clicking the "Add a Custom Cover" link.