Prototyping a Mobile App? Start Development With These Steps

Developing a mobile app is no small investment, and no small feat, either. Landing on a prototype that’s development-ready requires the input of UI designers and UX pros, constant feedback loops between designers and developers, user testing, and numerous iterations. Thankfully, getting from idea to MVP has gotten quite a bit easier with interactive prototyping tools like InVision and Sketch.

Say your prototype is looking pretty polished. You’ve experimented with your UI, made rounds of design tweaks, and gotten some valuable feedback from user testing. While it’d be nice to press a button and have that prototype come right to life as a finished mobile app that’s ready to download, the next steps you take are crucial to your app’s future success.

Have you considered whether your app will be fully native or cross-platform? Do you have a strategy to implement analytics from the outset, so improving your app down the line can be driven by solid learning and user data? What about user testing, something that’s best done early and often? Read on for some tips to keep your app’s success on track as you move into the coding phase.

1. Start coding

You’ve got your polished prototype, and you’re ready to start bringing your designs to life. What goes into the development of an app, and who do you need to get it built?

This is the most complex phase—expect many iterations, with a constant feedback loop between your designer and developer along the way. Both the front-end interface and back-end server support of your app are written as a coordinated effort, and the process usually involves quite a bit of back and forth. On the front end, you’ll be making decisions about how your app’s functions come to life with code—its computing logic. At the same time, any back-end engineering—server-side components your app needs to run, like a database, APIs, etc.—are integrated.

If you’re going the native application route, we’ve created two general guides to development of iOS apps and Android apps that identify the requirements, skills, and development environments required for each.

Tip: Scalability is important to consider when kicking off the development phase. Your application should be written to support growth from the very beginning. “Architecting” an app early on could prevent you from having to completely rewrite it when it needs to grow.

2. Testing and quality assurance (QA)

As you begin developing your prototype, testing will help you refine your app in two areas: user testing and QA. These both address avoidable bugs, lost users, unfavorable reviews, and more. Test-driven development (TDD) will help you ensure quality, reduce bugs, and create a more maintainable code base from day one.

With user testing in particular, you’re going to get valuable perspectives of your prototype before coding even starts. A/B testing lets you stack up two versions of your prototype to see which one users prefer and why. This can help inform UI and UX designers about how your users actually use your product, learnings that can validate your assumptions or show you where you have room to improve. Engage a user testing pro to help you determine what’s best for your app.

Beyond how users feel about your app, you’ll want to test for bugs and performance issues with QA testing. Reworks and fixes are almost inevitable, but you can significantly cut back on engineering time spent on those fixes with a good round of software testing. QA testing will help you uncover any bugs deeply embedded in your code that aren’t immediately apparent on the surface with user testing, the kind of bugs that can take weeks to fix once an app is already in production.

Software testing is rarely a one-size-fits-all process. Be sure to find the right mix of specific software testing approaches that work for you and layer them so you’re covering all your bases, from security and integration testing to load and stress tests that indicate how your app will perform under heavy traffic.

Tip: It’s helpful to have QA professionals work closely with your developers from the outset. Don’t bring QA in too late in the game; the sooner they’re able to run tests on modules of code, the more smoothly the process will go. QA is also vital in making sure the app is built to your specifications, another reason why it’s valuable from day one.

3. Go cross-platform and reach more users

Now that you have a working prototype, have you considered whether you’re going the native, hybrid, or cross-platform route? While native apps have numerous advantages, creating a version of your app that’s cross-platform (meaning it’s not built with OS-specific tools but is able to appear and function natively on any OS) makes it available to more users. This is the perfect time to determine which strategy is the best first bet for your app.

Developing a native app for different platforms can ensure that your app runs as smoothly as possible on both iOS and Android devices, but creating those two separate native codebases is expensive in terms of time and cost. Developing your prototype to be cross-platform allows you to get your app on more platforms with a single codebase while still taking advantage of all the hardware and OS capabilities of each (e.g. API-based features like iOS Beacons or Android Fragments).

Many companies choose reliable, high-performance cross-platform frameworks like Xamarin and Phonegap, which allow you to build your app in one language (bonus: HTML and JavaScript are more commonly known than OS-specific languages like Kotlin or Swift) that gets compiled natively. Also, look into next-gen components-oriented JavaScript frameworks like React Native, React’s mobile-focused version. Apps built with React Native can render native views that don’t require a webview thanks to the components-oriented nature of these new frameworks and performance optimizations like the virtual DOM. That allows them to achieve near-native performance with the same cross-platform benefits as traditional cross-platform and hybrid apps.

Tip: Opting to go the cross-platform route? Make sure you’ve considered how your app’s data structures, UI, and functionality will look and feel on each platform (iOS, Android, and Windows). This is something you can easily do in development platforms like Xamarin, which provide native UI builders and access to native device APIs.