A very simple question but with many different answers when asked. Kubernetes should provide a ground set of concepts that allows interoperability of systems and a shared knowledge in the ecosystem. In any kubernetes distribution, a Pod or a Service have the same definition, this is not the case for application. As end-users are mainly managing apps, it's time for kubernetes to get a representation and a definition of it. 
The sig-apps community came to an agreement to provide this missing piece. They created a new Application resource and its controller. This talk is bringing light to this new upstream resource, the features it provides with concrete examples, and the next steps and how to get involved.