Rockstar
Cleaning the outside glass of a window can be both dangerous and tiresome. This window design by Jung-In Jang is perfect for those with lots of windows and who live in rainy areas.

Each time you slide the windows, a built-in squeegee cleans the glass for you. You obviously need to clean the inside yourself, but it's usually less dirty and easier to reach than the other side.

So instead of hiring people to dangerously clean those glass skyscrapers, all they need to do is wait for rain (or hose down the building) and ask the people inside to slide the windows!