Analyze an iOS app for memory optimization

I need someone that is really,really good at iOS memory optimization. I am getting ready to release a quiz type app at the iTunes store and I want it to work well. The app consists of about 20 ViewControllers. Particular issues that I have include: - Sometimes upon tapping a button, it “lights up” for 10 to 15 seconds before executing. The log shows a ViewController: dealloc once it executes. - Occasionally, not all images are shown. - You must login to Facebook to run the app. I want to make sure Facebook is properly being accessed. Please quote an hourly rate. Also, provide me with reasons you are qualified to do this. If you do not have a lot of experience, then please do not bid.