Is there something you've dreamt up which, if manufactured, would really help you or someone else?
My current two are a magnetic, waterproof magnifier to read shampoo bottles in the bath.
Also window wipers worked from inside the passenger seat of the bus so I could see out the window instead a murky blur.
These are mine for now. Over to you.
Wicked Little Letters? (funny film of a long-forgotten case)