> For the complete documentation index, see [llms.txt](https://docs.luciq.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.luciq.ai/ios/setup-luciq-for-ios/setup-application-performance-monitoring/setup-screen-loading/ui-kit.md).

# UI Kit

Set up screen loading performance tracking for UIKit view controllers with Luciq. Monitor load times and identify slow screens across your iOS app.

Luciq automatically captures the time it takes for any UI Kit screen to load. This covers the time for any View Controller between `viewDidLoad` and `viewDidAppear`, which includes the following lifecycle methods:

* `viewDidLoad`
* `viewWillAppear`
* `viewWillLayoutSubviews`
* `viewDidLayoutSubviews`
* `viewDidAppear`

### Spans

Luciq will automatically show spans and operations that occurred during the View Controller loading; these include:

* Network Requests
* Database Queries
* UI Kit Lifecycle methods

### End Screen Loading

You can also define custom points in each View Controller to manually inform the SDK that screen loading has ended.

{% tabs %}
{% tab title="Swift" %}
{% code overflow="wrap" %}

```swift
APM.endScreenLoading(for viewController: self) // self here is a reference to a UIViewController
```

{% endcode %}
{% endtab %}
{% endtabs %}

<br>


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