Top 10 Open-Source iOS Libraries for App Development

If you know even the basics about iOS app development, you’d know that it is a herculean task. 

Third-party libraries can save you a lot of time and effort.

You don't need to waste your time reinventing the wheel. Instead, you can easily integrate these third-party, open-source libraries into your project and get your app rolling.

You can find suitable libraries on platforms like GitHub or Bitbucket. And they can be integrated into your project using tools like CocoaPods or Carthage.

You can find libraries that can be used for UX, downloading images, displaying cool navbars, and even for modern calendars. But, finding the most suitable one from the pool of options is tough. 

To make your job easier, I did some deep digging and found the top 10 open-source iOS libraries. These will make app development a breeze.

How did I choose the top 10? 

The list features iOS libraries that are the most popular among users. I did not solely rely on my own judgment. I also took into consideration peer recommendations as well as statistics from CocoaPods. (CocoaPods collects anonymous user data after library installs.)

Now, let us get straight to business.

Top Open-Source iOS Libraries

1. Realm

Realm is a mobile database that runs on several platforms other than iOS. It runs directly inside phones, tablets, and wearables too. 

And when it comes to persistence, it is a stellar cross-platform alternative to Core Data.

You get a data browser to explore the database files. And it is faster, as well as easier to work with when compared to Core Data. Also, the library launched a platform that syncs data between apps in real-time.

It is among the most popular iOS libraries, and developers who want to do anything related to data persistence must know about it. 

Get it from GitHub - https://github.com/realm/realm-cocoa. 

2. SwiftlyJSON

Swiftly JSON does exactly what the name suggests. It helps in swiftly parsing JSON in Swift. 

Parsing JSON in Swift is tricky. But Swiftly JSON saves you from all the nested ifs and typecasting issues that make deserializing model objects difficult. 

The optional wrapping is done for you automatically. And probably that’s why it is the second most popular Swift library. 

Get it from GitHub - https://github.com/SwiftyJSON/SwiftyJSON.

3. Chameleon

Chameleon by Vicc Alexander is a lightweight flat color framework for iOS. 

However, don’t underestimate its power and potential. If you really have design in mind but don’t want to spend hours wrapping your head around RGB values, Chameleon is the library you’ll love. 

You can quickly get the required color combinations and, thus, a beautiful interface. And the right colors that are easy to get with Chameleon also add to your user’s experience. 

Plus, it can be used on both Swift and Objective-C.

Get it from GitHub - https://github.com/vicc/Chameleon. 

4. Kingfisher

Kingfisher is a pure Swift library for asynchronous downloads. And the lightweight library can be used for caching images from the web. 

Kingfisher downloads the required images from the URL and sends them to both memory and disk cache. And it is displayed in UIImageView, NSImageView, NSButton, or UIButton. 

A must-use if you are working with display images, it also offers some additional options. It shows placeholder images while downloading, shows a system indicator, and has extensible image formatting, processing, etc. 

Get it from GitHub - https://github.com/onevcat/Kingfisher. 

5. Hero

If you are working with an iOS view controller, Hero is the library that will be your savior. It is a breezy layer over UIKit’s confusing transition APIs. With Hero, custom transitions are no longer a trouble for developers. 

It works by first checking the source and destination views for heroID. For matched view pairs, the transition from the old to the new state is done automatically. 

In the case of unmatched pairs, however, Hero can also develop animations. You can use the heroModifiers property to define animations. And also, ensure that these animations are controlled interactively by user gestures. 

Get it from GitHub - https://github.com/HeroTransitions/Hero. 

6. RxSwift

If you are looking for reactive programming in Swift, RxSwift is a simple, elegant, and powerful library for the job. 

Its basic job is to easily enable the composition of asynchronous operations and event/data streams. You can consider it as a Swift side alternative for ReactiveCocoa. 

Though it is quite similar to Rx’s original version, some of its features have been adapted for better performance. The adaptations also ensure that the integration with the iOS environment is pleasant. 

RxSwift has a steep learning curve; however, once you get the hang of it, you would be thankful that you took the time to understand this gem of a library. 

Get it from GitHub - https://github.com/ReactiveX/RxSwift. 

7. AFNetworking

When you call a certain API to fetch data from a server or database, the process is called networking. And this call process is not something that you’d call convenient. 

But that was before Matt Thompson decided to run the AFNetworking open-source project and give iOS app developers a breather. AFNetworking is among the most popular open-source libraries and gets updated every day. It is lightweight, makes iOS developers’ lives easier, and is fast too. 

It basically uses blocks and GCD (Grand Central Dispatch) and significantly improves an apps’ responsiveness. It also optimizes the code with higher performance primitives.

Get it from GitHub - https://github.com/AFNetworking/AFNetworking.

8. Alamofire

Alamofire is another popular HTTP networking library.

Another one? Is AFNetworking not enough? 

Well, Alamofire is AFNetworing’s Swift-based cousin. And it is a tad bit trendier than its big bro. Also, it is entirely built using Swift and has no traces of inheritance from its Objective-C counterpart. 

Alamofire provides an elegant interface over  Apple’s Foundation networking stack. And this simplifies many networking tasks. For example, network communication for a multiplayer game. And also, everything about JSONS (i.e., uploading, downloading, and getting)

With this easy and effective library, you don’t have to deal with URLSession (though basic knowledge would be good). And you can also significantly reduce boilerplate code.

Get it from GitHub - https://github.com/Alamofire/Alamofire. 

9. Lottie

Animations are essential. Period. But for iOS app developers, using UIView or CoreGraphics for animations is a pain. It takes too much time, and it is no less than a challenge.

However, you can thank the team at Airbnb because their open-source iOS library, Lottie, is here for the rescue. 

Lottie lets you load and render animations in the bodymovin JSON format and utilize a designer’s creation in your app. With Lottie, parsing Adobe After Effects animations becomes a breeze. And your applications become a lot more fun and memorable.

Get it from GitHub - https://github.com/airbnb/lottie-ios.

10. MagicalRecord

Dealing with core data is cumbersome, confusing, and challenging. But, MagicalRecords open-source iOS library makes it extremely easy and even elegant. 

It works like a wrapper. Hiding all the irrelevant stuff from the developer. It basically cleans up the core data and enables quick and simple one-line fetches. 

It provides convenient methods to wrap boilerplate code for set up, query, and updating of core data. Thus, making the developer’s job easy. 

Get it from GitHub - https://github.com/magicalpanda/MagicalRecord. 

Caution While Using Open-Source iOS Libraries

Before you use any iOS library for app development, here are the two things you should know:

1. Don't use a library just for the sake of using it. Or if you want to use just a small part of it.
   
2. Always make sure that the library that you are planning to use is actively maintained and supported. Otherwise, it can cause troubles later down the project's timeline.