Just talk to him. Tell him you'd like to get more recognition from the higher-ups for the work you've done on the app. He might not be aware he's taking credit, just trying to streamline the information without explaining the nuts and bolts of how an app gets built. If he seems cagey, defensive, or tries to minimize your effort then take that as a signal that you should either be OK with him taking all the credit or look elsewhere.
In my experience, the higher ups are usually pretty aware of this kind of thing and will figure it out, and if they don't they're just going to get annoyed at you if you try to point it out.
Also, just an observation -- if you can build an app from scratch, in 3 months in Bali no less, can do freelancing to pay the bills, and don't like the corporate hierarchy -- what's stopping you from just doing your own app?
In my experience, the higher ups are usually pretty aware of this kind of thing and will figure it out, and if they don't they're just going to get annoyed at you if you try to point it out.
Also, just an observation -- if you can build an app from scratch, in 3 months in Bali no less, can do freelancing to pay the bills, and don't like the corporate hierarchy -- what's stopping you from just doing your own app?