How to build APK in Android
Prepare your projects
Make sure that’s no error, or force close in every features in your application. You can ask your friends, QA teams or your boss to check it.
Do Inscpection
Remove unnecessary function or file in your app folders to reduce size of the app. The more less size is better.
Generate .apk file
Easily by clikcing build → generate apk→ then choose folder to locate
Now, the file is ready to install in your external android devices