I wish I didnt have to download the stories everytime

My son loves all the stories. I like ves most of the features but I absolutely HATE having to download stories everytime I exit the app. I download all the stories using house wifi but then go to use app out and about are the stories there nope have to use my cell data to download again. Please fix this problem

Malissa brown about My First Books Snuggle Stories, v1.1.0