Apple is planning a major overhaul of its App Store, including the introduction of a new subscription model for developers and the implementation of a paid search ad program, SVP Phil Schiller indicated in interviews ahead of the company’s Worldwide Developer Conference in San Francisco next week. The move may help to offset flagging iPhone sales. To encourage developers to sell their apps on a subscription basis, Apple plans to change the current 70/30 revenue-sharing structure, potentially increasing the developer’s share.