Fold Gags.

A foldable is the first phone where a wallpaper can have two states. This theme uses that: a piano lid that closes, a clam that shuts on its pearl, a crocodile that snaps, a tortilla that becomes a taco.

The gag only works because the hardware does the animating. Nothing here is a video file or a live wallpaper — it is a still image that happens to be completed by closing the device, which is why it never costs battery.

Expect to demonstrate these to other people. It is the theme most likely to start a conversation.