Account and sign-in help
Use the same KTool account in the web app, browser extension, and mobile app. Your Kindle destination, saved settings, and plan access belong to that account.

Sign in to the right account
If your articles or subscription seem to be missing, check the account shown in Settings. Use the same sign-in method you used when creating the account. Signing in with a different email or provider can lead to a different account.
Recover access
For an email-and-password account, use the password recovery option on the sign-in screen. Check your spam folder if the email does not arrive. If you originally used a sign-in provider, try that provider again.
You can manage your password in Password settings where applicable.
Update your Kindle destination
Your KTool sign-in email and Kindle delivery address serve different purposes. Set the delivery destination in Send-to-Kindle settings and approve the personal KTool sender in the Amazon account for that device.
Find a missing subscription
Check Subscription settings. For an app-store purchase, use the Apple or Google account that made the purchase and try Restore Purchases in KTool's purchase screen. See subscription help before buying again.
Close your account
Use the account deletion option in Settings when you are ready, and read its confirmation carefully. Handle any recurring subscription through its billing provider first; deleting an app is not a cancellation method.