What it is is an application that tells you not only what the weather is, but also how to dress for it. By giving an example for an outfit, you an adjust your clothing to the weather. Also you can buy the clothes in the outfit directly because all pieces are connected to a webshop. The good things about it is that you don't have to buy, it's just an option. You can also choose just take some garments you have that are alike to the ones in the picture.
Why it is cool, is because it can be really helpfull for desperate women all over the world. Also the fact you can buy but don't have to is great. Just copying the example can be enough and help you have less stress int he morning. Maybe in the future this is the way we'll dress, eat, go out and everything else, just by asking how to do it.