建议用户更新到最新版本

We currently have an iphone app in the app store. We release version updates periodically, about once every other month or so, sometimes more often. Most of the times, the updates are not large, just added bits of functionality, bug fixes, etc. Sometimes however, there may be major changes (so far it had happened once, about a year ago and it's about to happen again).We currently have an iphone app in the app stor