Opening one app from another app without closing the app

Question

In the home page of my iphone app, there is a button added. When that button is clicked some other iphone app needs to be opened in a new viewcontroller (with out closing the parent app).There will be a back button on this view controller. When the back button is clicked, the new viewcontroller which is showing the another app needs to be closed and our parent app's home page needs to be shown.

Please give me some ideas on how to do this. I googled for this i didnt get any solutions.

Thanks, Raja.

Answer 1

-- the following applies to iOS versions previous than 4.0 :)

Actually, there can be only one iPhone application running at once (with exceptions of Safari, Phone and some other system applications). The iPhone Human Interface Guidelines say so:

Only one iPhone application can run at a time, and third-party applications never run in the background. This means that when users switch to another application, answer the phone, or check their email, the application they were using quits.

However, if you only need to e.g. show a webpage, you can do it using UIWebView

Also, if you need to open another application, you should use URLs as pointed by Steve Harrison. This will, however, close your application. The recommended behavior in this case is to remember your application state and restore it when the application is run again, as Nithin writes.