安装前理解应用内购买
在安装应用前，了解内购标记、订阅、试用、消耗型项目和付费墙行为。
Not all free apps are free to use
Many apps are free to download but require payment for core features. Before installing, look for in-app purchase markers, subscription language, trial prompts, and user reviews mentioning paywalls.
免费下载不等于免费使用
很多应用可以免费下载，但核心功能需要付费。安装前应查看内购标记、订阅措辞、试用提示，以及用户评论中是否提到付费墙。
Know the purchase type
Consumables, one-time unlocks, auto-renewing subscriptions, and trials behave differently. A consumable may disappear after use, while a subscription renews until canceled. This difference matters more than the initial download price.
理解购买类型
消耗型项目、一次性解锁、自动续订订阅和试用的规则不同。消耗型项目用完可能消失，订阅则会持续续费直到取消。这比初始下载价格更重要。
Pay attention to first-run screens
If an app shows a trial or annual subscription before meaningful functionality, slow down. Look for a close button, read the period and renewal terms, and confirm cancellation steps in Apple account settings.
注意首次启动页面
如果应用在展示实际功能前先弹出试用或年费订阅，请放慢操作。寻找关闭按钮，阅读周期和续费条款，并确认在 Apple 账号设置中如何取消。
Use risk signals together
IAP alone is not bad. The risk increases when aggressive paywalls combine with unclear developers, vague descriptions, poor support links, excessive permissions, or external payment requests.
组合判断风险信号
内购本身并不等于风险。真正需要警惕的是强势付费墙与不清晰开发者、模糊描述、无效支持链接、过度权限或外部付款请求同时出现。