This is the first time, I worked with Parse and must say its a nice to have tool for any web developer. Parse minimises the task a lot in terms of backend and hosting.
Parse has a lot of options to choose from and one can choose to use the only required ones.
Well, I started of with hosting only, for one of my Facebook applications. They even have a SDK to integrate the Facebook SDK with them. I have not yet implemented their SDK yet, but docs show its simplicity of use.
I have started working on a BackboneJS application integrating Facebook and hosting in Parse. That went quite smooth. Actually Parse has extended BackboneJS to provide another SDK of their own to create frontend applications.
Happy coding.