I am new to ios development and doing development in ios4.0.1 and xcode 3.2.3. My application should capture other application's launch time and (close) end time. how can we do this? Any help will be appreciated.
Thanks Pushpa
For apps in the app store, the answer is "You can't". The best way to think of other applications on iOS with respect to yours is: don't. You can't access their data, you can't see if they're running, you can't control them, and you can't change them. Apps are well and truly sand-boxed as a fundamental design decision in the current setup.
About the only thing you can do is trigger their launch with a suitably formatted system URL. If a Wikipedia application has registered the scheme wiki, you might be able to launch and communicate some simple data by having the system load the URL wiki://articleName, but that's the limit. You don't even know what application will be launched, only that one has the wiki handler.
Jail-broken iOS systems are a whole different matter, but I'm assuming you're not working on those.