If you have a subscription, cancel it first before deleting your account.
If you're not sure if you have a subscription, login through the NaturalReader web app and go to Account > Subscription & Billing > Refresh. If a subscription is active, select Cancel Subscription.
If you subscribed through Google Play or the App Store, the subscription must be cancelled from your mobile device's subscription settings.
Once your subscription is cancelled, you can delete your user account.
While logged into your user account, select Account from the side menu
Select Delete My Account
If you are sure you want to proceed with the deletion, select Delete My Account to confirm
How do I change my Google Account or Apple ID login to an email login?
You can do this by deleting your user account and re-registering using the email sign-up option.
Deleting your user account will erase your account's current contents including your document and audio Library. If you have a subscription, it remains active during this process.
Visit follow the steps above to delete your user account through the web app. Then, visit here for steps on how to register your account by email.