"Well that's developer's problem, isn't it?" Obviously not as the developer got full payment. It's both the developer's and client's problem. "Yes, that's how

"Well that's developer's problem, isn't it?" Obviously not as the developer got full payment. It's both the developer's and client's problem. "Yes, that's how contracts work. Welcome to the real world. How is it your problem that the developer agreed to an impossible task?" Did you miss the part where the client wasn't going to get the app/code unless he paid? As soon as the dev said he needed payment or else the submission was a no-go, it became the client's problem. The "contract", if you could even call it that - good luck to the client trying to seek legal recourse with it, was poorly thought out. "Welcome to the real world."