First of all, we would like to say that the version on the Mac App Store is exactly the same as the version you can purchase from this website, so if you have already purchased it here, there is no need to do so on the App Store.
As far as updates are concerned, each user will be notified through the appropriate channels. This means that if you purchased OmmWriter Dana II from the App Store, you will receive a notification just like any other application. If, however, you purchased OmmWriter from our website, we will inform you of updates via email. Because the channels are separate, it is not possible to integrate licenses from the website to the App Store, but we will make sure that each user receives word of when an update is available.