I found the UI confusing. Two useless slash screens? Why not dump the user right into the app?

Why can't I browse the backgrounds like a standard gallery with swiping?

Thanks for the comment! The two splash screens are because of Android: the second one is the wallpaper selector, there's no way of leaving this out. While HPSTR is set as wallpaper, you'll never see one again.

The app downloads random images each time it is refreshed, so there's no gallery - this is by design.