Notezilla is available in 2 flavors. Cloud and Non-Cloud. If you have purchased the Non-Cloud version that doesn't allow syncing notes between devices and multiple computers, then this is the reason, you are seeing "45 day trial" when creating the cloud account. You can learn more about it here: http://www.conceptworld.com/Notezilla/BuyNow
The cloud account is yearly subscription, while the non-cloud is a one-time payment. In order to keep all your devices in sync (Automatic sync happens every minute), you would need to purchase the cloud subscription.