Create an Offline Function

Is there a way to make it so the app downloads for offline functionality?

Not at this time.

If the app is upgraded to premium is it possible to add it to the Google Play / App Store?

Check out the link below. There are two places to inquire about your question.

One is just to email hello@glideapps.com. The other, in the FAQ’s, it’s a link to a form to make the request. https://glide.typeform.com/to/ZAy2d4