Google has just announced that Android 4.4 KitKat will come with a default SMS app to be used, which the user can select from system settings.

Moreover, in a bid to make things easier for everyone, the new Android version will make existing application programming interfaces (APIs) public.

Google further points out that many developers working on Android apps have built SMS applications using hidden APIs, a practice the company frowns upon. The explanation is quite simple.

"Sending and receiving SMS messages are fundamental features on mobile devices and many developers have built successful apps that enhance this experience on Android. Some of you have built SMS apps using hidden APIs - a practice we discourage because hidden APIs may be changed or removed and new devices are not tested against them for compatibility," Google explains. "So, to provide you with a fully supported set of APIs for building SMS apps and to make the user experience for messaging more predictable, Android 4.4 (KitKat) makes the existing APIs public and adds the concept of a default SMS app, which the user can select in system settings."

"This means that if you are using the hidden SMS APIs on previous platform versions, you need to make some adjustments so your app continues to work when Android 4.4 is released later this year."

Google further notes that developers must keep several things in mind. First of all, if their app is not selected as the default SMS app, they must disable the ability to send new messages from the application. Without the ability to write to the SMS provider, the user would not be able to see any sent messages in their default SMS app.

To enable their application to send and receive messages, developers can display a dialogue using the system as a host, thus allowing users to select the app as their default SMS application. Developers are also advised to include a message that allows users to change their default SMS app.

It's also worth highlighting that any existing app serving just for backup and restoring SMS messages will be unable to do it on Android 4.4, because the ability to write to the SMS provider will be limited to the default SMS app provided by the user. The only way such and app (that only backs up and restores SMS messages) can work is if it is also set as the default SMS app, so it can write messages in the SMS Provider.

Google is further asking Android developers to update their apps "as soon as possible" based on this new information. The necessary SDK components for Android 4.4 will become available for developers "soon," in order to allow them to compile and test their changes on the new OS version.

Otherwise, Google made no mention of when the new Android 4.4 KitKat will be ready for public release, but it shouldn't be too long now. Stay tuned for more updates as soon as new information becomes available.