I had a memory leak in my app and after hooking up my iPhone and running ‘Profile without building’ I got a Instruments Leaks screen pop up that looked like this:

Not knowing how to find the offending line of code I found clicking on the calltree stack and selecting ‘Hide System Libraries’ and ‘Show Obj-C Only’ options helped me see what was wrong.

And here was the offending class.

And double clicking this line brought up the actual line of code.