How to Prepare Graphic Assets in Your Android App to Publish in the Play Store
When you publish an Android app to the Play Store, you interact with Google Play’s Developer Console. The essential step in this interaction is the step in which you upload your app’s APK file. It’s the essential step, but it’s by no means the only step. You must also use the Play Store’s Developer Console to describe your app in detail. In the Developer Console, you answer many questions about the app, and you provide some important graphic assets.
Creating an icon
When you create a new project, Android Studio puts some default attributes in your AndroidManifest.xml file. One of them is the android:icon attribute:
<application android:icon=“@mipmap/ic-launcher” … >
Along with every app that you submit to the Play Store, you must submit screenshots. As of early 2015, you must submit at least two screenshots. The Developer Console has slots for phone screenshots, 7-inch tablet screenshots, 10-inch tablet screenshots, and TV screenshots. Each screenshot must be JPEG or 24-bit PNG with no alpha transparency. The minimum length for any side is 320 pixels, and the maximum length for any side is 3840 pixels.
There are many ways to take screenshots of your running app. The easiest way is to use Android Studio’s built-in Screen Capture facility. Here’s what you do:
Use Android Studio to run your app on an emulator or a real device.
At the far left edge of the Android tool window, look for a little camera icon.
When you hover over this icon, you see the words Screen Capture. That’s a good sign!
Click the Screen Capture icon.
A new window appears. The window shows a screen capture of your device or emulator. You can click the Save button immediately. But you can also click Reload, Rotate, or make several other adjustments.
If Android Studio’s Screen Capture facility isn’t your thing, you have several alternatives. For example, you can use your operating system’s screen capture facility to take a screenshot of a running emulator.
Launch your app in the emulator.
Click the emulator window (so that the emulator window is the active window).
While you hold down the Alt key, press the Print Screen key in the upper-right corner of the keyboard.
Depending on your keyboard’s make and model, the key might be labeled PrintScr, PrtSc, or some other variant of Print Screen.
Open an image-editing program.
A great image-editing program for Windows is IrfanView. The program is completely free.
Press Ctrl-V to paste your new screenshot into the image-editing program.
On a Mac
Launch your app in the emulator.
This tells the Mac that you intend to take a screenshot.
Press the spacebar.
This tells the Mac that the screenshot will capture a single window.
Click anywhere inside the emulator window.
Your computer creates the screenshot and places it on the desktop.
You can use your development computer’s screen capture facility to take a screenshot from a physical device. On your development computer, download a program named Android Screen Monitor. Connect the physical device via USB to your development computer. When you run Android Screen Monitor, the program displays the physical device’s screen in a window on your computer screen.
In theory, on devices running Android 4.0 or later, you can press the Volume Down and Power buttons simultaneously to take a screenshot. The trouble is, the exact sequence of presses and button holds varies from one make and model to another. Check your device’s documentation (and other sources) for more info.
Your options for creating screenshots are endless. The paid versions of the Genymotion emulator have their own screen capture facilities. If all else fails (and, in fact, all else seldom fails), you can get screenshots from running emulators and devices using Android Studio’s Terminal window. Search the web for adb shell/system/bin/screencap.
Creating a feature graphic and a promo video
If your app is featured on the Play Store, a feature graphic appears on your store listing page. Your feature graphic must be a JPEG or 24-bit PNG file with no alpha transparency. Its dimensions must be 1024 by 500 pixels. You can also put a promotional video on the store listing page. To do so, type the promotional video’s URL in the Developer Console’s Promo Video field.
This blog page has lots of advice on creating feature graphics. The key is to create an eye-catching image that promotes your app without replicating your app’s screen. You should also make sure that the image looks good no matter what size screen displays it.