The Google Search mobile app for iOS and iPadOS now features customizable widgets. There are tons of themes available to arrange the widget nicely on your wallpaper.
There are two options for the widget: a square one with the ability to start a search and a rectangular one, where the Lens buttons, voice search and start incognito mode are also available.
The update is being rolled out gradually. For me, for example, it still has not appeared.
Several themes will be available to choose from: earth, travel, abstract art and solid colors. There are a lot of pictures inside the selections. There are also basic themes in black and white. You can choose a specific option, or you can set an automatic daily shift.