This web application was developed from NASA's EOSDIS for displaying high resolution satellite images. It has a very interesting timeline that permits to study not only the present but also past years, starting May 2012.
With Worldview, you could check relevant data as air quality, vegetation, floods, storms, fire, smoke events, …
It's in alpha state so don't be surprised if some strange behavior arises here or there! As far as we know it's based on base layers and overlays. The user selects a base layer for displaying the satellite image with a defined map style (not always) and after there's the possibility of adding more data from different sensors in the form of “overlays”. With the eye icon, it's very easy to review different information.
It seems that the application has multiple options for overlays and base layers, and enables the user to download the result of the available combinations.
Easy and with great options, for sure Worldview is one of the best applications in this field!