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What are we working with?

This is a really simple app, albeit quite a broken one. Obviously the breakages are deliberate, but they are all things I have seen in real, shipping code. The app shows a table view containing garish images of popular internet acronyms.

When one of the rows is tapped, a detail view controller appears, showing the image at full size. Every time you tap on the big image, it adds one to a count of how many times that image was tapped, and that count is shown in the original view controller.

That’s it – that's all the app does. I haven't even used a storyboard, because I want all the problems to be visible (and fixable!) in Swift code.

And how bad are the problems? Well, if you run the app on a device, you'll probably find that it crashes after you’ve viewed several pictures – on my iPhone I get about two-thirds of the way through before it gives up.

You might also notice that scrolling isn’t smooth in the table view, particularly on older devices. If you scroll around a few times iOS might be able to smooth the scrolling a little, but you’ll certainly struggle to get it a flawless 60 frames per second on iPhone, or 120 frames per second on iPad Pro – the gold standard for iOS drawing.

I hope you’ve never seen an app that manages to have all these problems at the same time, but I can guarantee you’ve seen apps that have one or two at a time. The goal of this project is to help you learn the skills needed to identify, fix, and test solutions to these common problems, so let’s dive in now…

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