Creating an “app” Using Android Studio :
An apk (Android project) contains all the files that comprise the source code for your Android app.
This post shows how to create a new project using Android Studio.
Create a Project with Android Studio :
1. In Android Studio, create a new project:
o If you don't have a project opened, in the Welcome screen, click New Project.
o If you have a project opened, from the File menu, select New Project. The Create New Project screen appears.
o Fill out the fields on the screen, and click Next.