There is no account to delete. This app has no login — everything it stores lives on your device.
Nothing it stores has ever been sent to us.
Delete the app from your iPhone: touch and hold the icon, tap Remove App, then Delete App. That removes every piece of data the app created.
To clear your data but keep the app, use Reset in the app's settings. Both are immediate and neither needs us to do anything.
Your App Store purchase history belongs to Apple, not to us. Deleting your data here does not cancel a subscription — do that in Settings → your name → Subscriptions.