Deleting an account will immediately render access to that account invalid. Deleted accounts can no longer access or edit their projects, nor can those email addresses be used for a new account.
Currently you can absolutely delete your account through your phone.
Here are the steps:
1. Log into your Headliner account on the Headliner app on your phone.
2. On the top right, click settings.
3. Click Delete Account, then confirm.