If you have a WP Ultimo license, you can cancel its renewal at any time you want. Just follow the steps below:
Access your Freemius account page through the link you received in your e-mail after buying WP Ultimo:
Use the email you provided during the purchase and your password.
This is your Account Page inicial screen:
To cancel your subscription, on the menu on the left, go to Renewing & Billing.
Click the arrow on the right to open a side window. Then, you should select the option that will cancel the auto-renew.
The system will show you a confirmation message.
If you are sure you want to cancel your subscription, just click the Cancel Renewals button. After this action, you will be asked to answer a quick survey.
Done! Your subscription won't be automatically renewed.
You will have a valid key until your subscription expires. In case you want to reactivate your subscription, you will need to do it manually.