In a technological world where IOS app development is changing daily, users’ expectations for app performance continue to grow. An application that launches slowly or reacts slowly to user interaction may look non-functional or slow to the user. An application that makes several massive network queries may raise the user’s data costs and deplete the iPhone’s battery. Any of these actions might irritate consumers and cause them to delete the application.

Which parameters should you keep in check?

App Size

Although app size does not affect in-app performance, it affects first-time users seeking to install your app and is a persistent burden on your customers’ limited mobile disc space. It directly affects the following:

• The time required for consumers to download and install your application.
• The mechanism via which consumers may obtain your application (Cellular or WiFi).
• The amount of disc space required to keep your application installed on a user’s device.
• The cost varies according to the size of your app, how they downloaded it, and their mobile plan.

App Launch Time On iOS, there are three distinct kinds of app launches:

• Cold — Occurs after a device restart or when the application is not loaded into memory.
• Warm — Occurs when the application was ended recently or is only partly loaded into memory.
• Resume — Occurs when the application has been halted, and memory is full

The operating system optimizes warm launches and resumes greatly, so we should concentrate on cold launches, the longest of the three. 

The breakdown of the cold launch is as follows:

• During the first 100 milliseconds, iOS will perform system-level tasks required to start your application.
• Create your views, load your content, and produce your first frame within the next 300ms (with placeholders if necessary).
• After 400 milliseconds, your application should be started and operable. 

It is OK to continue to load new material to replace any placeholder views in your first frame.

Responsiveness of Apps

Instantaneous user interaction response shows that an application supports the user’s workflow. 

When an app reacts in real-time to gestures and touches, it gives users the impression that they are directly affecting features on the screen. If an app does not react instantly, consumers question its functionality.

The human perceptual system is good at distinguishing motion and relating successive events to their causes. A person quickly recognizes an interval between two occurrences as a pause. A delay of as little as a few tenths of a second might give users the impression that an app is inactive and unresponsive. 

Apps must respond rapidly to the user’s activities to keep them engaged. Monitoring app responsiveness might include examining a variety of data, including:

• load times 
• update times
• scroll hitch rate
• app hangs

Memory Access

Applications, the operating system, processes, and the kernel all share a finite amount of memory. Because this limited resource is shared, an app that consumes excessive RAM might degrade the user experience throughout the device. 

The operating system warns applications that use excessive memory (which you may detect programmatically) and will terminate them if required.

Batteries Used

The battery is another mobile device resource that is limited and shared. In contrast to desktop computers with a steady power source and laptops, mobile devices must operate for long periods without recharging. 

In addition, batteries lose charging capacity over time, making this resource even more scarce. When an app uses too much power, it may force users to charge their phones at inconvenient times. This poor experience may cause customers to abandon your software if they believe it does not deliver enough value to compensate for its power draining effects.

Network Efficiency

Network performance may include a broad range of subjects; however, the following are some critical app performance indicators that should be monitored concerning networking:

• The number of network requests issued by your application
• The speed or round-trip time (RTT) of each network request 
• The quantity of data requested by each network request

Conclusion:

Monitoring important metrics and seeing their trend over time facilitates the maintenance of a fantastic app. It provides the information necessary to evaluate where you should invest your time and money to reduce user friction. 

There are many more metrics you can measure and tools you can use than those mentioned above. Still, hopefully, this article has set you on the path to creating an iOS application that is brilliantly optimized. 

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