I wonder if it is possible to use a new Instagram Graph API only for hobby purpose(small java application). The main aim is to process only user's data that is currently log in on instagram(not other's user data). Generally I'm a beginner on this field and I try to determine my chances for writing this kind of application, because I've read that sometimes it is hard to get permission to API from facebook, so maybe somebody know how it works in practice?
I personaly suggest you to use new graph API, because older API support may be disabled in future and might be deprecated in future.
Moreover, Facebook does not give permission easily but you give proper & exact content if allows you and provide great support.