Android users, especially Samsung device users, may also have app back up service provided on the device. Please check it out and backup your app information.
Except this, sorry that since our editable drafts are saved on the individual device, you may be not able to retrieve those drafts if you change the device.
But if you've shared those collages to your PicCollage account previously, you can still save the creations from your profile.
Sorry for the inconvenience.