我发现以下链接很有帮助。它解释说，由于Home Screen应用程序现在像本机应用程序一样存储，因此它们有自己的存储/缓存。

I found the following link helpful. It explains that as Home Screen apps are now stored like native apps, they have their own storage/caching.

地理定位在第一次迭代时有效，但从那时起无法更新。

Geolocation works on the first iteration but fails to update from then on.

iOS 6地理位置和本地数据存储

主屏幕应用程序中的数据是现在存储就像原生应用程序一样。原生应用程序每个都有自己的沙箱，用于存储，备份和恢复数据。在iOS 6之前，主屏幕应用程序与浏览器中运行的同一个应用程序共享数据。如果用户清除缓存在浏览器中，应用程序的主屏幕版本也将丢失其数据。在iOS 6中，主屏幕应用程序的数据就像本机应用程序一样保存到沙箱中。备份和恢复正确处理数据，并在浏览器中清除缓存不会影响他们。

"Data in Home Screen apps are now stored like native apps. Native apps each have their own sandbox where their data is stored, backed up and restored to. Prior to iOS 6, Home Screen apps shared data with the same app running in the browser. If the user cleared the cache in the browser, the Home Screen version of the app would lose its data too.With iOS 6, Home Screen apps’ data gets saved to a sandbox just like native apps. Backups and restores handle the data properly, and clear cache in the browser will not affect them."