Summarize this article:

Once you are finished adding features and filling out content, you can build the app so that it can be ran on your Android device. The process will vary depending on what program you are using. If you are using an online app creation program, you may have to wait a few minutes for your app to be constructed by the program's servers.  You are generally provided with an APK file that can be downloaded onto your device. You will need to set your device to allow installation from unknown sources. You can allow this from your device's Security menu. Some app creation programs will email you the link to your app that you can open from your phone. Once you've installed the app on your device. Test it out to ensure that it is functioning properly. Send the APK file to some friends and family so that other people can help you test it. You are more likely to catch bugs and problems if you have more people looking at the app. Try to do things during testing that the app isn't made to do. This will help you find ways that your users may accidentally break your app. After you have tested the app for a bit, fix any errors that you come across or anything that doesn't work as well as it should. Your app should be easy to navigate above all else, so ensure that your app flows smoothly from one task to the next. Your publishing options depend heavily on what program and package you signed up for when choosing your creation software. If you chose a free service, your app will most likely be ad-supported, and may only be available through that company's app store. More expensive options allow you to publish directly to the Google Play Store and may even include promotion and marketing.  Consider releasing a free version with ads and limited functionality and a paid version with no ads and full functionality. This is one of the most common ways to monetize a mobile app. Make sure that your app has a good description and accurate tags. These tags will help users find your app through relevant searches, and are essential if you want your app to succeed.
Build the app. Test the app. Fix any errors. Publish the app.