An APK is an Android Application package file. Gradle, by default, builds a single APK, no matter what libraries you include. This compiled and packaged file includes all of the application's code (.dex files), manifest files, resources, and assets.

The library, within itself, comprises multiple copies of the same native code, optimized for the different architecture. This means that the library is a native binary with multiple architecture such as x86, x86_64, armeabi, and so on, all packed together. A developer can easily run the command unzip <your_APK_name>.APK to understand the content of an APK:

When your app, and the libraries it references, reaches a specific threshold, you encounter build errors that point to the app's limit of the Android App Build Architecture. The most recent Android build system displays an error, trouble writing output...

Earlier editions of Android OS used to run on Dalvik Runtime, which means apps used to compile at execution time. Post-Lollipop edition, Android has switched to Android runtime (ART), which means the apps are compiled beforehand, ensuring they are launched faster. ART, as the runtime, executes the Dalvik Executable format and dex bytecode specification. Apart from the launch, the entire consumer experience using the app is essential for app retention. One important feature is the battery - a dear feature of the phone.

An app which is greedy for power often finds itself in the position of either being uninstalled or lower rated when reviewed on the Google Play Store listing. Take a look at some of the most popular apps on the Store, including Facebook, which has had consistently bad reviews that quote battery drain as one of the top sources of...

The Android Settings menu options provide high level measurements of battery drain. However, to gain more insight into battery consuming apps, there are some tools that can be useful. Tools such as Batterystats and Battery Historian come in handy. Batterystats collects battery data from your device, and Battery Historian converts that data into a HTML visualization that helps you understand power consumption graphically.

Batterystats, was introduced in KitKat, but Lollipop brought a large dataset for the users which included data about every Wakelock action on the device.

Please reset the data and enable full Wakelock reporting to receive comprehensive information including how the device utilizes the battery, along with details about all the running processes.

Here are some of the commands you can run after connecting your device:

adb shell...

When you hear the term memory management in an Android app, it is basically the Random Access Memory (RAM). Managing the RAM is the most critical section in the Android app development process, as the physical memory is often constrained. The fundamental principle of memory management is to avoid a memory leak from your app.

In Android Studio there is a tool we can use to check the memory usage in the App. To check this you could follow these steps:

1. Run your app on an Android device connected to an emulator.
2. Open the Android Monitor tab in Android Studio situated at the bottom window.
3. Open the Monitor section within it, and you are there.

Here you'll be able to continuously check the memory usage of the app as and when the app is being used. The following image shows the memory usage for an app:

The preceding memory graph shows the memory used by a device...

Battery life is an excellent indicator of how your App performs. Apps without optimization can severely impact the battery life of a device. We've walked though in-depth analysis of battery drain in Android Apps. We also looked at Batterystats and the Historian tool to analyse battery usage patterns. Additionally, we explored memory optimization to ensure the app runs smoothly and stays off the memory leaking track.

In the next Chapter 3, Leap into the Android Support Library we will discuss Android Support Libraries.