IMPORTANT INFO ABOUT GOOGLE PLAY APP SIGNING
Read this important information about Google Play App Signing here, before you start uploading apps to Google Play!
1. Requirements for Android apps
- Android Developer Account
2. Uploading to Google Play
Uploading to Google Play is very straightforward. There's the application file (
.apk) and for single-issue apps, there's also an expansion file (
2.1. Creating a new application
When you login to your Android Developer Account, select ‘Create Application‘. This will bring up a screen where you can upload your
2.2. Uploading your first APK file
When you upload the
.apk file for the first time, you will be presented with the screen that allows you to select the
2.3. Uploading the OBB (expansion file) for a single-issue application
When uploading a single issue app, you need to upload a second file which is called an "OBB" or "expansion" file.
This is necessary because the maximum size for an APK file on Google Play is 50 MB. Because of that Twixl Publisher splits the app in two parts:
apk: containing just the Twixl Reader app itself
.obb: the embedded publication for the single-issue app
When you just uploaded your
.apk for the first time, Google Play doesn't allow you to specify the expansion file immediately. Before you move the application to production, click the "Upload new APK to production" option again.
You will now be presented with the following screen that allows you to select the expansion file:
Select "Upload a new file" in the "Use expansion file" option to upload the OBB file.
For more info about the OBB file and how to upload, see this article (Google Play Console Help, external link).
3. Add artwork
When both files are uploaded, you should also upload your artwork. A couple of things are required:
2 application screenshots:
These should be any of the following sizes:
- 320 x 480, 480 x 800, 480 x 854, 1280 x 720, 1280 x 800
- 24-bit PNG or JPEG (no alpha)
High Resolution Application Icon:
- 512 x 512 pixels
- 32-bit PNG or JPEG
- Maximum: 1024 Kb
The final steps to deploy your application to Google Play are: click ‘Publish‘ and ‘Activate‘ your application. It can take a couple of hours before your app will become available in the Google Play store.
4. Android Keystore
When you publish an app in the Google Play store, Google expects that app to be signed with a certificate. When you create an Android app with Twixl Publisher, we take care of creating this "keystore" for you automatically in the background. Every update of your app will have to be signed using the same keystore information (the app's "fingerprint" so to speak), otherwise it will not be accepted.
The keystore information will be saved as part of the build setting for that app. This means that, if you migrate to a different machine, you will have to make sure to also migrate the build setting, and also to never delete a build setting for an app that has been placed in the Play store. If you are migrating your app from another platform, check out this article.