One of the primary focuses of Kwilt is to free up space on your phone, therefore it would defeat the purpose if the application took up the same amount of space. Your files are not actually stored on the phone at all, so that all your mobile space stays free.
Here is how we do it; the drive or USB that is connected to your device holds all your photos and videos. This drive constantly stays online so that if you wish to pull up your files they are viewable on your phone without having to actually be stored on your phone. The only storage that the Kwilt app takes on your phone is the small thumbnail files of your photos and videos.