Do you mean folders?
In any event, the Android and iOS apps are pretty much abandonware at this point. Neither one of them works properly, but there's no one available to tackle the fixes. I don't understand why they haven't been withdrawn from their respective app stores. At this point, they're just damaging the jAlbum brand.
Most jAlbum skins are now fully responsive, so for viewing albums on a phone, you're better off just using the phone's browser.