Google’s latest mobile operating system, Android 4.4 (aka KitKat), is as satisfying to developers as the sweet treat it’s named after. The OS delivers a host of UI changes, feature updates and enhanced services to compete with the recent iOS 7 launch. There are also a few surprising rule changes for developers of messaging apps, particularly regarding Google’s decision to make the Hangouts service their default Android messaging app going forward.
It’s hard to overstate the impact of such changes on both users and app developers, considering the market potential of Android KitKat. In a rather audacious move, Google has designed its latest OS not only for the newest, most advanced smartphones, but for older devices as well, including those with as little as 512MB RAM. In fact, it’s possible that Android KitKat could find its way onto a billion smartphones.
Android KitKat is potentially the largest strategic divergence we’ve seen between Google’s Android and Apple’s iOS to date. Apple is ushering its users into the future with a high-end device, the iPhone 5s, which is chock-full of premium hardware like the blazing-fast A7 chip, while Android KitKat works smoothly on Google’s latest smartphone, the Nexus 5, as well as older and lower-end devices.
According to Android Chief Sundar Pichai, Google’s goal with KitKat was to make “one version of the OS that’ll run across all Android smartphones in 2014.” Given the sheer size and device variability of the Android ecosystem, this is a rather stellar feat.
KitKat also continues Google’s efforts to more tightly integrate its various services (search, play, maps, billing, analytics, etc.) into the Android operating system, and having them seeded across as many devices as possible. Impressed? There’s more. A partial list of what Android KitKat offers includes the following:
These changes bring great news to users and app developers, however, there are also challenges. Some of the biggest hurdles for developers—and certainly the ones demanding immediate attention—are all the new changes related to SMS apps.
Starting with KitKat, Google Hangouts will become the default messaging app for Android devices. Hangouts integrates a user’s SMS and MMS presence, as well as video calling, all within a single app. Hangouts even lets users send animated GIFs.
Given its standard default status and functionality, millions of users can be expected to stick with Hangouts, at least for the time being. Developers of competing SMS apps must rise to this challenge quickly. To do so, they’ll need to closely follow Google’s many new rules. The most important of which are listed below:
1. Users must choose a default SMS app
With KitKat only, this designated default SMS app may now receive the SMS_DELIVER_ACTION intent or the WAP_PUSH_DELIVER_ACTION intent (for MMS messages).
2. There can only be one default SMS app at any time
If an app is not chosen as the default SMS app, Google wants the developer to disable the option for that app to send a message. If not disabled, any message sent through this non-default app will not be visible in the user’s default SMS app.
According to Senior Android Engineer Brian Tsai, developers will want to create a dialog box that requests the user select their app as the default SMS app, making the decision as easy for them as possible. Tsai also told me that many apps are not intended to behave as a standard (default) SMS app, but still want to send out SMS messages. These apps are likewise impacted by the new rules and will require coding and design changes.
3. SMS backup and restore are impacted
The new rules also impact apps that backup and/or restore a user’s SMS messages. As the Android Developers Blog specifies, “any existing app designed purely to backup and restore SMS messages will currently be unable to restore SMS messages on Android 4.4 [if it is not the selected default app.]” This is compounded by the fact that SMS and MMS functions are not handled exactly the same in every situation.
4. No more hidden APIs for SMS
Google is now also strongly encouraging app developers to not use “hidden APIs” to support SMS functions, as these may not be tested or supported going forward. With KitKat, Google now provides a standard public API set for building a SMS app.
Overall, this a big deal for developers. Go to Google Play and type in SMS. There are hundreds, maybe thousands, of such apps available. Fortunately, Google is actively publicizing the many SMS app changes, posting in both text and video blog formats the necessary instructions to function properly in this new environment. Many existing apps will require both back-end and UX changes, with the new UI design itself necessitating changes to existing SMS apps.
Don’t be misled by the “dot” release—Android 4.4. This is a sizable update for the platform, one likely to impact nearly every app developer and every leading handset maker. As Consulting Architect Caldwell Shine told me, Android KitKat will reduce fragmentation and benefit mobile providers such as Sprint, T-Mobile and Verizon.
There are approximately a “million new Android activations every day,” according to Shine. “When you combine that with the backward compatibility of the new OS, it’s clear that Android KitKat could have a radical impact on the developer community.”
Despite all the necessary work, the changes related to SMS apps should result in a better experience for users. Associate Android Engineer Elliot Chenger claims he is excited by this challenge. “With Android KitKat, developers have a much greater opportunity to create a more robust and better user experience around text messaging. This definitely closes the gap with Apple’s iMessage service.”
Much like Apple’s new iOS 7, Android KitKat is a cleaner interface that focuses on content and search greater than ever before. Developers and designers will have to do the same.