The what3words app widget is only available for iOS devices, with more options and flexibility for iPhones operating on iOS 14.
To add the widget to your device, press and hold the what3words app, tap 'Add widget', then swipe left to find it.
Alternatively, press the home button, then swipe right to open the page with a search bar at the top (Today View). Next, scroll down until you see an ‘Edit’ button. Tap the button and scroll down the 'Add Widgets' page until you see what3words. Tap the green cross, and tap 'Done'.
For iPhones operating on iOS 14, touch and hold anywhere on the screen until the apps jiggle. Tap the plus sign in the top corner of your screen and scroll or use the search bar to find the what3words widget. Tap to select it, choose from the three different widget sizes, then tap ‘Add Widget’. Tap and hold to drag the widget to any of your phone screens.