> there should never be more than one button ... which you have to look at, because the position and function changes. There is no muscle memory with dynamic U

> there should never be more than one button ... which you have to look at, because the position and function changes. There is no muscle memory with dynamic UI. I recall a visually impaired woman who couldn't hail an Uber. I could tell she was very fast with the old UI. But, the button had shifted. She was going to call her Husband to drive over from Oakland to pick her up in San Francisco. Instead, I showed her where the button was.