Which Android version/phone can control per-app access permission? The only reason I am still using an iPhone is due to the fact that most Android phones did not allow control of per-app access permission. The App Ops feature was once there but pulled.

I know some Chinese Android phones, such as XiaoMi and Huawei, provide the app permission feature. Is the feature available in mainstream Android phones, such as the Nexus, Samsung, LG, HTC ... for latest version of Android 4.4.2 or upcoming Android L?
No, App Ops is not available on Android any more since Android v4.4.2 and probably won't be reintroduced with Android L but might be resurrected some time later. It was apparently dropped as some apps would stop functioning so the user experience would suffer.

Some optimal solutions:


Find a device that is supported by a Custom ROM like Cyanogenmod. This aftermarket firmware includes a feature called Privacy Guard that works similar to App Ops. 
My preferred solution: Buy a phone that is rootable and use the 3rd party solution called Xprivacy. It is an Xposed module that has the most advanced permission control with a very dedicated developer. As long as your device is rooted you will be able to use that tool on any ROM > Android v4.0. Downside: Not easy to handle.
Use one of the other optional methods for permission management listed and compared by the Xprivacy developer here.