To cancel your Photo Resize Pro subscription, just go to the Photo Resize app and downgrade to Pay-as-you-go.
All the images the app resized will not be changed. However, your original images will expire 60 days after and you will no longer be able to restore the originals back.
The 60-day period is applicable to the date when the images have been resized. For example, if you’ve resized batch 1 of images on October 10 and batch 2 of images on October 20, you will no longer be able to restore batch 1 images by December 10 and batch 2 by December 20.