I was in the very exact problem: To use the API only for my internal projects. I wanted to avoid to creat a "developer token".
But... then a new scenario came into place: I am sharing my source code with a friend, so I will access *my* account and she will access *her* account.
I will run my code in my laptop and then I ship her my code, that will run on her laptop.
Question: Is the developer token supposed to be "secret" or "public"?
I mean... Is it "public" so every "install" of the application uses the same token because it represents "the application"? I mean: should I have *one* developer token "for the project" and pass her my "developer token" as it represents "the application", and the I do my outh credentials and she does her oauth credentials?
Or the "developer token" is supposed to to be secret because it does not represent "the application" but "the installation of the application", so she has also to register as a developer, wait the 3-5 days, etc, etc. so she uses not only her own oauth credentials but also her own developer token?
(PD: For the google team of the API developers: I think using in-house probably is a very common use-case and using a set of "my own credentials" without making it so complex to auth to use this API probably would help many users).