He pressed a button on the wall and a servant appeared.

This approach has important benefits; for example, buttons can appear and disappear according to the context.

Once the video has started playing, the 'S' button will appear on the right-hand side of the bottom bar.

He tapped more buttons and a second, identical pattern appeared beneath the first one.

He pressed a button and the rows of lights appeared on the barrel.

A button appeared on the last corner, on the side facing him.

The President pushed a button and the waiter appeared to remove their plates.

She tapped the buttons and the pool appeared, seen from behind the falls.

Her hair turned black, and a button appeared in her forehead.

German buttons appeared in 13th-century Germany as an indigenous innovation.