There’s no need to worry about that. You can always access all your creations even if you cancel your premium plan; you just won’t be able to make use of the premium features.

When you cancel your premium plan, you’ll lose access to the following features which are considered important by the community:

• You’ll no longer be able to download your geniallys and you won’t have access to new premium templates. 
• You’ll no longer have access to the privacy control feature. This means that all the geniallys that you published privately will become public and won’t be password protected. You won’t be able to organize creations into folders and all your geniallys will return to the Creations section of your Panel.
• Even if you cancel a plan, the audio files you’ve added to your geniallys will remain. However, if you need to replace them, you’ll only be able to add audios from a link or from SoundCloud.
• You’ll lose all the aforementioned features. In addition, the personalized items you’ve got in your Brand Kit section will disappear: you’ll no longer have personalized fonts, your logo, the loader, or the images you’ve uploaded to this section. You’ll also lose access to the statistics of your creations.

Creations downloaded during your subscription period will remain on your device as you downloaded them and won’t be affected.