Product review (3 stars): It exists, and it works, so hooray.
I'm just glad this exists! We needed it - my house hosts an array of visitors at different times of the year; when it's just me or my roommate, we generally hand-wash the dishes and use the dishwasher as a drying rack. So a clear announcement of CLEAN or DIRTY was needed.

Two complaints:
1) You can't choose black or white (though either one suited our machine).
2) I'd have put a bit more of a lip on the the part that you slide; it's a little tricky to get a grip on it to move it over.

But, once it's moved over, it's moved over, and doesn't slide back easily. :)