I have just heard that - " push notification " is possible in iPhone
I need following details.
Thanks in advance for sharing your knowledge with Stackoverflow family & me.
The sort of background processing you're looking to do is not possible with push notification.
Push notification allows you to notify the user of something. An example would be a Twitter client that sends a notification when the user receives a direct message on Twitter.
Push notification can not react to things happening on the iPhone when the app is not running. Instead, it depends on you having a server that determines when to send a notification and then sends one.
I'm not seeing any need for background processing in your application. If you store the user's initial location, the next time the app loads you can get their location and calculate the distance between the two. If you're looking for the route travelled, you're out of luck unless you make a deal with AT&T like Loopt just did.
Push notification is not really for that purpose, you should read up on push notification in apples site here http://developer.apple.com/iphone/library/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Introduction/Introduction.html, its more for when theres data like a m essage for your user, you can have the user get it without having them open t he application. Now for your purpose, why cant you store the location when htey close the app, once the reopen the app you can reget a location, use the previous location and the new location to calculate the km travelled?
Although only tangentially related to this discussion, I think you might be interested in Loopt's agreement with AT&T to track user's iPhones (for a monthly fee).