I remember trying out an Android sleep app that had a "flat" design. It never worked. On the last day of the trial I realised why - part of the flat "design"

I remember trying out an Android sleep app that had a "flat" design. It never worked. On the last day of the trial I realised why - part of the flat "design" was actually a button that I also needed to press. I was so annoyed I deleted the app.