applications control access to collections of services by the use of an API key. So in your case, the application is just a logical construct.
But applications can also be html/js files hosted within DreamFactory. In that case the application is also an actual application, not just an access control.
Regarding lodash not being found -- are you on Windows? V8 scripting is not currently available in Windows -- the library doesn't compile correctly. We've got a guy working on getting it recompiled to work in Windows.