There already are several non-advertisement clients though. You can't charge to get a feature another client already has unless your other features are worth that cost
If he is writing the app so he can learn and just be a corporate drone (no judgement, I'm a proud corporate drone) then give it away for free. If he wants to learn how to be an entrepreneur, he should do an assessment of what's out there and find a competitive advantage that would make people willing to pay some money.
