Costs Of Converting an iOS App to the Android Platform
Developing an application for one’s personal or business needs comes with many major questions that must be answered. One such critical decision that must be made is whether to develop for the iOS platform, or for Android. There are several key differences between the two platforms, and developers typically go about development differently. However, there are times when it might be more advantageous to port an app from the iOS platform to Android, or vice versa. This is a very feasible operation; however, it is important to note that one should carefully consider the bottom line of porting costs from one platform to another.
This analysis must take the system frameworks, programming languages (Objective C for iOS versus Java for Android), Software Development Kits (SDKs), and APIs into account. There are other factors - such as whether the app will use an iOS user-interface (UI) versus the Android UI, how the app will interact with unique device hardware elements, how security should be handled in ported code, and the type of Android device that is is to be supported. An additional factor for cost is the fact that iOS devices require an understanding of Objective C/Swift and the entire Cocoa Touch API, along with the iOS SDK and a powerful Mac Computer to run the Xcode IDE (Integrated Development Environment).
This is compared with the relatively straightforward methodology associated with using an Android IDE (e.g. Android Studio), and the Android SDK. A thorough analysis must also consider the closed source/proprietary nature of the iOS platform and its large set of APIs versus the open source nature of the Android platform - and what that means for application conversion.
Are There Programs That Can Convert Apps From iOS to Android and Vice Versa?
It can be argued that one of the quickest and most cost effective ways of porting an iOS app to Android - or vice versa - is to use one of the many available platform porting software services that convert bytecode for Android into the code that will work on iOS systems. However, the general consensus is that such programs do not work very well, due to the vast differences between Objective-C/Swift (used to program iOS apps) and Java (primarily used to program Android apps). While Objective C is the C language with Object Oriented features added to it, Java is loosely based on C. Hence, it is important for a human programmer, that is well versed in software engineering, to sift through the code manually, convert Objective-C classes to Java classes, and debug the application at run-time.
Though programs can help with this task, no program to date can fully port iOS code to Android code 100 percent. It is important to note, however, that programs, such as Google’s J2ObjC open-source tool, are making great strides in code conversion, in being able to allow the utilization of Android code in iOS platforms via direct code translation (for non-User Interface code).
Converting Requires Translating Many Areas Which May Affect the App’s Performance
With human languages, it is well established that, in the area of translation, even the most robust programs like Google Translate often fail in total linguistic conversion. In the same way, converting a mobile app requires more than just a simple platform-to-platform UI transfer, or a simple, automated code conversion. A total, thorough conversion requires bytecode-by-bytecode translation, and may require re-writing certain areas of the application from scratch to fit the new platform’s architecture.
Areas such as authentication (e.g. apps that use an iOS device's fingerprint scanner versus Android devices that are devoid of such a feature), general security (e.g. typical code vulnerabilities present in Objective-C and Swift that aren’t present in Java), scalability & interoperability (i.e. Java is a highly scalable, platform-independent and platform-interoperable language, while Objective-C and Swift are typically faster), and UI-programming, etc. must be accounted for. Also, like all Java-based apps, the Java Virtual Machine (JVM) is used to run Java applications on Android via Dalvik or ART (though the use of the JIT compiler is also used) versus iOS’s native apps which don’t require interpretation at run-time.
As has been noted, Apple released a new programming language that is now used to write native iOS apps: Swift. As a language based on C, Swift shares many similarities with it’s predecessor- however Swift is more static, and according to benchmarks, is slower than C, while faster than Java.
Even when using automated tools, converting an app may require a re-engineering of certain application modules from scratch, such that adopting a Conversion Software Development Life Cycle (C-SDLC) may be beneficial. As noted above, when converting from one platform to another - from the standpoint of assessing an app’s functionality and performance - it is always important to note how a platform’s underlying programming language performs in various benchmark tests.
Design Factors May Need Adjustment to Suit the Different Platform
One of the most critical factors that must be assessed when porting an application from iOS to Android is the application design, which includes the graphics, UI, and feel of the application that may be native to a specific platform. Due to the inherent differences between Android and iOS devices, the specific design of an application may require extensive work in remodeling the UI of the application before porting can be successfully carried out.
Different Rules for Design and App Behavior
While the iOS has some specific design rules associated with its mobile elements (e.g. icons), Android is more open to various design paradigms. These critical platform differences must be taken into account when seeking to port apps from one platform to another. For instance, iOS apps are usually square (with rounded corners) and flat. Android’s use of transparent backgrounds for icons allows designers to work with a variety of shapes. Its Material Design creates design possibilities that are not realized in iOS systems. The animation styles of each platform are also different, thus directly converting an app from one platform to another may require some remodeling of the application’s UI, design and overall look and feel.
Different Button Sets for Navigation Require Different UX Features
One of the more obvious differences between iOS and Android platforms is the physical presence of a “back” button on Android devices, which must be included in iOS apps in the UI due to a physical lack of said button. It is thus considered inappropriate to include such a button in an Android app. There are a myriad of other differences that are significant from a designing standpoint. As noted by Beacon Zone’s Simon Judge, “The main problem areas are round buttons rather than square, tabs at the bottom rather than top, lists with right pointing arrows, incorrect icons for common functions and back navigation via a top back button”. In addition to this, the status bar, navigation bar (specific to iOS devices) and app/tab bars (specific to Android devices for the latter) are different with iOS devices as compared to Android devices, which must be taken into account when designing the UI as well. Another factor to assess is the differing specifications for platform grids and navigation systems, which are different in iOS devices when compared to Android devices: The Material Design (Android) specifies a specific 8dp grid for general uses, and certain apps use either tabs or a drawer menu, along with a lower navigation bar.
Wireframes May Need to Be Adjusted to Suit the New Platform
The overarching UI blueprint of an app on one platform will need to be readjusted - or completely refashioned - to suit a new platform. This is due to the platform differences outlined above, as well as the fact that UI programming, API and SDK software engineering implementations may also be very different on the iOS and Android platforms, resulting in a potential need to redo both wireframes and the underlying code.
Software Development Factors May Require Revisions or Changes
As noted above, in addition to the choices that must be made regarding iOS versus Android app designs, the overall development choices that were made throughout the SDLC might require revisions. This is due to the fact that the iOS and Android platforms - along with Objective C/Swift and Java respectively - were developed to operate optimally with different hardware architectures and underlying hardware elements. For instance, Java uses a smaller heap than its iOS counterpart, which along with slower performance, might affect app functionality, and thus must be taken into account.
The Android OS also allows easier interfacing between apps, which means that less code is needed to tap into powerful APIs that, for instance, allow end-users to “share” information with others via email or social media. Contrasting this, iOS’s APIs are stricter and “closed,” but are well documented.
Another critical mention is the hardware functionality and extra features present in Android that are not present in iOS, which may require a developer to change the code in order to make use of such features. Such features include automatic Bluetooth LE device recognition by the Android platform versus iOS’s pre-configured Bluetooth device recognition via UUID. Android can also use Near Field Communication (NFC) - which some iOS devices have for Apple Pay - which is a unique feature that gives Android users access to many advanced features that an app developer may want to leverage.
Architecture May Need to Be Revised for the New Platform
While the graphical architecture of an application may need to be readjusted to work smoothly with a new platform or hardware device, the underlying code architecture may need to be revised as well. One of the most important parts of application porting from iOS to Android (or vice versa) is debugging and QA (Quality Assurance) testing.
Each Platform Uses Different Code to Build With
As has been noted, Android uses mostly Java for its apps (though C and C++ can also be called or used with the Native Development Kit), while iOS uses Objective-C and Swift. A critical factor related to the underlying language is the fragmentation issue with Android devices. While iOS devices will typically range from an iPhone and iPad - all with the latest iOS patches - Android devices are somewhat famously fragmented, ranging from many different types of devices and OS versions. This makes it difficult to develop an app for any one Android device or Android OS version, which must also be taken into account.
Summary
The desire to convert an iOS app to Android, and vice versa, can be a sound business decision when one is able to correctly deploy workflows that optimize the advantages of the target platform. This can be done to reach a broader audience and to positively affect the overall corporate bottom line. That said, it is important to note that automated software cannot completely convert an app from one platform to another, and that unique design elements exist for each platform that will require some design and UI remodeling. Along with code translation, revising the underlying architecture of the app can help to smoothly port the app in a way that benefits end-users and leverages the special elements of the target platform.
