We’re sorry to hear that your account is blocked. This can sometimes happen for security reasons — often because your password has been incorrectly entered 5 times.
To unlock your account, please try resetting your password. To do this use the "Forgot your password?" button on the app sign-in screen. An email containing instructions on how to reset your password will then be sent to you. Open the email, follow the link in it and enter your new password.
That should sort you out! You can now enjoy the awesome onoff App again!
If this didn’t work for you, please contact customer support, using this contact form.