Haven VPN has no accounts
The app does not ask you to sign in and stores nothing about you on our servers. Everything it keeps is on your device.
To remove all of it, uninstall the app: Settings › Apps › Haven VPN › Uninstall. That deletes the app's entire storage, including its settings and anything it had cached.
If you have any question about data the app may hold, write to pivotmasterapps@gmail.com.