The mobile app of Apple 12 system charges 30% more than the mobile app of Android system. What are the applications and what are their characteristics? Are all paid apps relatively expensive? For example, bike-sharing/Auto, Takeaway, Alipay, WeChat, and some app stocks, securities and futures with relatively large capital flows. Which ones are overcharged by Apple and which ones are not? As users, how can we distinguish and avoid it?