Is it possible to run application in background forever in iphone?

I know with ios 4 it is possible to run application in background as per this documentation http://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/BackgroundExecution/BackgroundExecution.html

this documents states that if application updates user's current location in background continuously then it is possible to run it in background.but is it necessary that we have to use only CLLocati开发者_开发问答onManager for updating current location?can we user other apis like google latitude apis for updating current location?then also it is possible that application is able to run in the background forever?

As far as I understand from the document you posted, if you define the UIBackgroundModes with a value of location in your info.plist, "the system should allow the application to run as needed in the background". So, the first answer is yes, the application can run in the background and it will run indefinitely (up to battery life). This could be easily checked, actually.

Anyway, it seems to me that this kind of functionality is "reserved" to GPS-like apps and that Apple is really concerned about its usage:

For applications that require more precise location data at regular intervals, such as navigation applications, you need to declare the application as a continuous background application. This option is available for applications that truly need it, but it is the least desirable option because it increases power usage considerably.

so, I understand that Apple will screen really thoroughly all apps that activate this mode in order to assess if they really need the continuous update or do not (and in this case, possibly, the app would not be let in into the App Store).

Now, to answer the second part of your question, I think that one way that Apple will know if your app really complies with the rules, is its usage of CLLocationManager. The risk is that if you use another service, then Apple could think when reviewing your app that you just need background time without needing to constantly update the location.

But this is just a guess...