Something that will grip and twist to get stiff lids off jars, but combines useful add-ons like a bottle opener and a can opener (I just want it all you see).
The same device adaptable to grasp and turn ordinary sink taps on and off easily.
A 5-section bin unit for a kitchen to allow sorting compost, paper, plastic, glass and non-recyclable kitchen waste, that looks desirable, fits under a counter, is easily cleaned.
A foldaway dining table and chairs set that is actually comfortable to use and sit at, as opposed to the many designs that currently exist and are hideously uncomfortable.