I am developing an app where I have to detect whether there any app which is already running on device. I want the list of all running apps. I made R&D on this topic but I found nothing. Is there any way to do this?
I think in a non-jailbreak app you can not do this.
However for a jailbroken app you can do : Return a list of running background apps/processes in iOS
As this app in iTunes does the same as you need, so you can go with above.