Apple Watch

The watch app on iPhone.

The Apple Watch app shows a short list of actions and readings, plus complications you can put on the watch face.

Setting it up

The watch app installs alongside the iPhone app. Choose what appears on it from Settings → Apple Watch on the phone.

Complications

A complication puts one reading or one button directly on the watch face. Add it by editing the face on the watch and choosing this app as the source.

It shows stale values

watchOS decides how often a background app may refresh. Opening the app forces an update; if complications lag behind, check the watch still has a route to your home.