If you sign up for a Pro subscription, you can remove the branding card at the end of your mashes and the watermark on your snippets, among other cool features.
To remove branding only from the video you're mashing, do the following:
Tap on the "Branding Off" button at the bottom of the video editor.
Tap on the teal checkmark/Save & Share button.
Done! This specific mash won't display our branding.
On the iOS app:
On the Android app: