xCode: How to monitor CPU usage for any running third party app

Question

Is that even possible. I just wanna know how much CPU the current running app is using up. I know, for my own apps i can do that with xCode easily. But how about third party apps. I only want to know CPU usage while the app (or game) is running.

Answer 1

Open the Instruments app and use the Activity Monitor instrument.

On the top left drop-down menu, select your iPhone and choose "All Processes". Do not select a specific app that isn't yours, it will not work.

You will never be able to connect the Instruments app (or the Xcode debugger for that matter) to an app that isn't signed with your development certificate. Even with your own app, it will not work if the app comes from the App Store (because apps on the App Store are not signed with your development certificate). This is a security feature to make sure you don't mess around with apps you don't own. It may be possible to bypass this restriction on a jailbroken device (although I have never tried).