We <3 the design team at Clue. They made the app as beautiful and sleek and not pink as it is, but they also create the beautiful illustrations you see here on helloclue.com.
They were kind enough to make some uterus phone backgrounds for Clue users—because why not? Uteruses (uteri?) are beautiful.
On most phones you should be able to save the image below to your phone by tapping on it. Then you can set the image as your phone background from your photo app, or in settings. Happy tracking.