A Beginner’s Guide to iOS App Development
App Builder Appy Pie: When it comes to app development and choosing the platform that you want to develop the app for, the two major platforms that you really need to think about are the Android & the iOS. Making this decision also defines the audience that you would be targeting with greater clarity. Android dominates the global smartphone market with 83% of the market share, however, iOS has higher number of apps in the app store.
In spite of the dominance of Android devices in the market, it doesn’t mean that only Android has all the benefits for an app developer.
So, before we jump in and start helping you develop a stellar iOS app, let us talk about why you must develop an iOS app.
- iOS is a lot faster than any Android device
- iOS apps run a lot smoother with almost no glitches
- iPhones or iPads function pretty much in the same way, whereas Android devices vary in their construct & functioning wildly
- iOS apps earn much higher revenue from the App Store
- All iOS apps can be used in any MacOS. An equivalent functionality is missing in case of Android
- Using an iOS device, the iOS apps can be shared with friends and family. Another feature that is not yet developed for Android
Things to do before writing an iOS app
While it might be tempting for you to dive head first and start writing your iOS app because that is where all the action lies. Following processes can get tedious but there is merit in it.
It is important that you chalk some time out beforehand to setup the project in the right direction. Now, you might think that it is eating away into your time right now, but trust me, you are doing yourself a favor and saving a lot of time in future.
The points I am going to list below are especially important if you have a team of professionals working on app development. These considerations would definitely reduce potential frustration of your team and increase your app quality.
#1 Create Coding Style Guides
A Coding Style Guide specifies the style and conventions that would be followed while coding in any specific language.
This guide would have guidelines for decisions like whether you should use tabs or spaces, the system of naming the variables, or specific conventions that you would be following for particular languages, for example in Swift would you be using Classes or Structs.
We can’t really deem a coding style right or wrong. You can set up the coding style that is unique to you, but while working with a team, it is important that they follow the style guidelines that you set up. Doing so would ensure that your code stays uniform and is easier to read.
If you are having trouble setting these up, some of the companies have made their coding guidelines for Swift & Objective-C open source and you can take a look at them before setting your own up.
#2 Plan the App Architecture
Before you jump up and dive into the process of coding, it is imperative that you first decide upon and fixe the architecture of your app. Having a good app architecture makes your app more testable, comparatively easy to comprehend, and brings down the maintenance costs.
You can opt to go for the traditional MVC architecture if it suits you, and if it is something fancier that you are looking for then you can go for MVVM or VIPER.
You can find lots of resources online which can describe these architectures and you would be better equipped to take care of this point.
#3 Create an App Folder Structure
While it might seem like nothing to dump everything in a single root folder (and easy), but if you do not follow any kind of structure you would be left with hundreds of source files ending up in one big indescribable heap.
To avoid this eventuality, it is a good idea to develop a folder structure for the app which would be defined and determined by the architecture of your app.
Once you have a clear idea of it, first create the folders as groups within the group and put the name of your project in XCode’s Project Navigator.
Next, for each of the groups, create links to an actual directory in the path of your project by opening their File Inspector on the right, clicking on the little grey folder icon, and then creating a new subfolder sporting the name of the group in your project directory.
Though while doing this, you may feel that it is only a minor thing, it actually makes your app a lot more structured and much easier to understand.
#4 Managing the Dependencies
When you are developing an iOS mobile app, it is natural that you would be using certain third-party libraries in your app.
Primarily there are three ways to manage the dependencies in your project.
This is the apt dependency manager for Swift & Objective-C Cocoa projects. The system has almost about ten thousand libraries and thus has the potential to help you scale any project in quite an elegant fashion.
The system is especially effective when it comes to the management of dependencies that are somewhat similar in their approach to RubyGems.
Git submodules are a great way to organize your dependencies as sub repos. The submodules have a clear advantage over Cocoapods, simply because submodules are sub repos.
This is big, because it means that git and git GUIs implicitly recognize them and an increasing number of them support working with them easily! Additionally, it also means that your dependencies stay connected in the ecosystem where the git repos exist.
However, like any other system, this too has its limitations. The downside of using Github Submodules is that your project would not have the source for code that you can depend on, in future. It only has a reference to the submodule’s repository which, in most cases is not even under your control.
This one is specifically designed with an intent to be the simplest way to add frameworks to your Cocoa application. It creates framework binaries leveraging xcodebuild but leaves the responsibility of integrating them on to the user. Though the approach of Cocoapods scores high on usability, but the approach of Carthage is particularly flexible and non-intrusive.
However, there is a big limitation in this system – Carthage only supports iOS 8 or later versions.
#5 Plan Suitable Schemes for the App
Schemes are responsible for communicating to the XCode which actions should happen when you initiate actions like Run, Test, Profile, Analyze, Archive, or any other action. What they basically do is map every action to a target and a build configuration.
Additionally you can also pass launch arguments like the language that the app would run in which is a pretty important point when you are trying to localize your app, and can even set some diagnostic flags for debugging.
#6 Create Appropriate Certificates & Provisioning Profiles
Yes, it is a painful step, but it is one of the most important steps and is imperative for testing and distribution of any iOS app. You require certificates for code signing in order to be able to run your app on an actual device. There are two kinds of certificates:
Every individual developer has their own development certificate and it is generated on request. Though XCode can do this for you, but it is better to try and understand the issue before simply going and pushing the “Fix Issue” button.
You need this certificate to be able to deploy the development builds to the devices.
Though it is possible to acquire several of these, still it is a good idea to stick to just one per organization, and then share the key for it through a specific internal channel.
You need this certificate to ship to the App Store or even to your company’s enterprise app store internally.
Provisioning profiles are arguably the most confusing element of the system. A provisioning profile determines and suggests the devices for which an application is correctly signed.
#7 Plan A Continuous Integration & Delivery Process
In recent times, it has become extremely important to set up a continuous integration & delivery process so that most bugs can be squashed in good time, at the right time in the development cycle, thus saving the developers a lot of time.
It is a development practice which needs the developers to integrate the codes into a shared repository multiple times in a day. Each of the check-ins is verified through an automated build, enabling the teams to detect any bugs early.
There are a number of tools like XCode Server, Jenkins, Travis CI and others that are great when it comes to implementation of continuous integration of iOS apps.
This is more of a software engineering approach where teams create software in short cycles making sure that the software can be reliably released at any time. The intent of this system is building, testing, and releasing the software quickly, and more frequently.
Top tips for iOS app development
Irrespective of the amount of experience or expertise you have in app development, tips and tricks can always come in handy.
1) Come Up with A Detailed App Development Plan
Any project that is not planned well is destined to fail with little chance for redemption. The points that we have discussed above would definitely prepare you and help you develop a great app. Also, before you start working on the actual app development process, it is important that you take the decision whether you want to develop an app for iPhone or iPad.
The next step is to define the goal of the app. A typical Apple user is used to high performing and usable apps; hence it is important that as an app developer you have the ability to develop a high performing iPhone app.
2) Stick To Simple
Keeping it simple is not as easy as you would think. When your app design is simple, the complications of the process are eliminated. It is of course possible to change the designs later, once you have gained some experience and have attained a measure of confidence. To begin with, however, it is advised that you begin with a really simple design that is comparatively easy to use while still being unique.
3) Coding Is The Hero
Your experience and expertise as a coder determine your comfort in app development. This difficulty was minimized by Apple in 2018 with iOS 8 and Swift. The now popular programming language, Swift is powerful and quite easy to understand while still being fast, safe, and interactive.
Coding has definitely become easier, but it still is the real hero behind the success of any app.
4) Incorporate Features Aimed at Increasing User Interaction
You must ensure that the app has amazing app interactions. Whether it is an iPhone app or iPad app, an app that has better user interaction is bound to fare well with your app users. This interaction quality must also be cohesive and translate well with website or any other digital estate that the brand has. This means that if your users are choosing products or services to buy from your mobile app, they can simply choose to make payments from their websites without having to look for the same products again!
What we mean to say here is that a good iOS app developer would know how to create iPhone apps to optimize the content on apps and on website.
5) Plan for Compatibility with All Versions
iPhone has a pretty loyal following and the iPhone enthusiasts tend to wait for new products and get in line to buy them as soon as they are available on the racks! This, however is sort of a luxury that not everyone can afford. In fact, there is a good population of iPhone or iPad users who, even today are using the older versions of iOS.
If the app that you are building is not compatible with all the existing versions of the, you stand lose out on a huge chunk of users. Not really a profitable deal, right? If you are doing this for a client, then you would be robbing them of the potential traffic in case any of the iOS versions don’t support the app. If you lose out on this sizeable traffic, you are bound to lose out on a proportionate amount of profit as well.
6) Create A Mobile Marketing Application
A typical mobile application is by design quite practical, primarily functional, preferably inexpensive, and highly interactive. If you are good at iOS app development, you would be able to make improvements to the app and add an edge to the application by integrating different social media and networks.
This is one of the most interactive methods of marketing that can help any business build a strong and meaningful relationship with the right kind of consumers. If you can manage to forge a strong customer relationship, the customers would definitely pay a lot more attention to the mobile app.
iOS mobile apps that include a strong marketing feature in the mobile app do a lot better than those apps that do not. It also goes a long way in helping the app owners target the exact medium where the audience or traffic is coming from and also in helping the app to be promoted on various relevant media.
7) Consider Battery Consumption
Battery consumption and battery life is one of the most concerning issues for mobile phone users who are planning to download or install an app on their device. An iPhone user has some expectations in this regard as well.
It is only logical that any high performing processor and process would eat away into the battery reserve resulting in low battery in quite a short period of time.
In general, most of the iOS app developers or agencies do not take into account the battery consumption and hardly do they ever take any special measures to save the battery life of the device. This in fact is one of the major reasons that may cause great dissatisfaction among the app users, annoys them, and may even lead to them abandoning or uninstalling the app.
Including some measures in this direction is bound to give you an edge over your competition. Though, it is extremely important that you test the app out before you launch it.
8) Consider iPad Apps
Most of the iOS developers who are working to develop apps for iPhones, should also think whether they want to add a version of the application for iPad. The cool thing is that iPad app development is not so different from iPhone app development!
There are a few differences though between app development for iPhone and iPad like resolutions, calling features, and in terms of rich designs.
Since the screen resolution and size of iPads are quite different from the iPhones so extra care must be observed while developing apps for the former to ensure that the richness of the apps is maintained across the devices.
9) Plan for The Traffic
When you have taken the efforts to create an app that is unique, useful, entertaining, interactive, and manages to satisfy the target customer group, it is only natural that it would receive positive and interested audience or traffic.
It is therefore important that you equip yourself with as many different approaches as possible to be able to respond to all that traffic immediately.
This means if you have recently announced a special deal, sale, or any offer, you should be ready to handle the upsurge in traffic from all the marketing channels that you have adopted. The app should not crash, should not hang, or become so slow that people abandon the app and never come back to it again.
The application in its construct should be robust enough to be able to maintain its functionality and user interaction levels to be able to handle the rush and the overall engagement.
10) Setting Up App Pricing & App Promotion
While you are trying to set the price for the iOS mobile app you have developed, there are a number of factors that you would have to take into consideration. Factors like time taken for development, cost of development, and the type of features that you are including in the app factor into the overall price of the app, as does the promotion of the app.
The promotion of the app is of critical importance in determining the success of the app. When you have channelized all your efforts and energy into creating a brilliant app, it is important that you spare some effort to make the right kind of people aware of your app.
The promotion strategies must be devised only after you have determined a relevant target audience for your app.
The tips that we have listed above can be great when you are planning to start developing iOS apps. However, apart from this set of helpful tips there are certain best practices that the industry follows, and you must too!
Best Practices for iOS app development
With time, in every industry, every process, even technology a set of best practices emerges that broadly helps the formulation of certain standards in the industry.
Listed below are some of the best practices that you must keep in mind while getting into iOS app development.
1. Plan Ahead Before Diving In
It’s a lot of fun to just begin coding and start developing your own iOS app because let’s face it, following processes is really boring and seems so mundane! However, if you take care to set things up the right way and devote the required amount of time in planning the app development process, you would end up saving a lot of time, energy, and of course money.
This planning needs to begin right at the start when you set up the coding style guides, timelines, pricing, and other such critical aspects. A well-planned app would always have greater chances of performing better.
2. Decide Which Minimum iOS Version You Want to Serve
When you are getting into iOS app development, you would have to think about all the versions of iOS that are there in the market and think about which ones you would be serving. It is obvious that you would be serving the latest versions of iOS to cater to the die-hard fans of iPhone and other Apple devices. However, you must also think about and decide what is the minimum iOS version that you want to serve. After all, there is a good chunk of users who are using the older versions of iOS and device.
3. Name It Right
In the process of writing high quality and clear codes for the iOS app, it is common for the developer to overlook the matter of naming principles.
It might seem trivial, but it actually is very important that you the basic conventions put forth by Apple for giving names to classes, methods, functions, constants, and other elements that form the code.
Make sure that the names are crystal clear, not ambiguous.
Refrain from using abbreviations, keep the names crisp and clear while following proper grammar. In addition to this, it is important that the naming principles are consistent all across the iOS app development project.
4. Plan the Architecture Right at the Start
Before you start writing the code, you must decide the whole architecture of the app. Whether it is the testability of the app, the understandability of the app, or the cost of maintenance, the app architecture plays critical role in it.
It is imperative that you do not shy away from architecture and design patterns. You must know about them and learn how to deploy them, so that you do not end up fighting against it.
The bottom line here is ‘Do Enough Homework’.
5. Incorporate an External Dependency
As a defined best practice for iOS app development, you must choose to add an external dependency to your project.
To begin with, you might feel that a single well-designed library would suffice, but as you roll out the next OS version you would actually see it all break apart. There is a good chance that you would get trapped under a truckload of maintenance jobs.
Instead of incorporating an external library in the official APIs, it is a better idea to first try and resolve any possible issues using Apple’s extensive frameworks.
6. Preserve All User Strings in Localization Files
Even when you are just starting out, make sure that all your user strings are kept in localization files. This means that all your translation jobs would be faster and better, of course and that you would have no trouble in finding the user-facing text in record time, enhancing the user experience!
7. Keep the Models Immutable
Keep the Models immutable and then leverage them to translate the types and semantics of the remote API to your app.
8. Minimize the Scope of Your Constants
Try and keep the scope of your constants as small as possible. Let’s say when you only need it inside a class, then it should live in that class.
You must keep the constants in one place which needs to be app-wide. True constants are type-safe and cannot be undefined or redefined later in the code, have a more explicit scope, and are available in the debugger.
9. Give Automation A Chance
Make automation your friend and it actually helps you maintain code quality. Whether it is about continuous integration or about continuous delivery, the eventual intent and goal of any sort of automation is to bring about a standardization and establish uniformity while squashing out any possible bugs early on in the process.
10. Setup Proper Log Levels
It is critical that the production builds do not log API tokens, or any other sensitive information like passwords etc. If you do this, all this information may end up being leaked to the public.
Before going on to release the app in the App Store, it is important that you take care and set up appropriate log levels.
If you log the basic control flow, you would have the ability to pinpoint all the issues that your users may be experiencing.
11. Vary the Environments for all Activities
As a practice, you must make sure that different environments are used when it comes to different activities related to the service including staging, testing, or any other.
Each one of them can be assigned their own base URL, log level, bundle identifier, provisioning profile, and other such elements.
Apple may suggest that you use the debug build configuration for development and create your App Store packages using the release build configuration, but you must keep in mind that a basic debug/release distinction will not suffice.
Relying only on the build configuration may be way too simple for the real-world apps. You can in fact, add more build configurations, through the ‘Info’ tab of your project settings in XCode.
12. Plan for Safety & Privacy
If the nature or construct of your mobile app requires you to store any sensitive data including passwords, personal details, or any authentication tokens, then you would have to store them all in a location so that they can not be accessed from outside the app.
As a practice make sure that you are not using Core Data or plist files on disk for this purpose, because they are not encrypted.
iOS Keychain can help you out in most of these cases. If you face any discomfort in working with the C APIs, one way out is to use a wrapper library.
13. Think Ahead About Crash Logs
It is important to make it a practice of sending all the crash logs on a server so that it can be accessed whenever needed. This can be implemented manually using PLCrashReporter in combination with your own backend, however, it is advised to make use of one of the excellent services that are not just popular, but effective as well.
After setting this up, you must save the XCode archive of every build you release. The archive would have the built app binary and the debug symbols in it that you would need to assign to the matched crash reports.
14. Engage in Analytics
Analytics are the real deal! It is imperative that you incorporate some analytics framework in your app. Analytics give you data, insights, and a clear indication of how people are actually using it.
You would be able to answer questions about the elements that are tough to find within your app and the buttons that get the most clicks, the features that people are searching the most for, and other such valuable information.