This blog tutorial will help you understand the new feature for the cover image. This is for iOS Only.
When we released the last update, which was a few months ago, we enabled a new feature. You can now change the header image on your timeline.
Go to the More section, then go on Me and you will see a blue bar up to. Tap on that and you will be able to change your profile image and change your cover image. You can either choose from our image packs or select an image of your own.
When you are, all done then tap on Save. Go back to the countdowns tab and you will see your changes.
Alternatively, you can just tap on the profile image picture from the countdowns timeline and it will take you straight to that feature.