This course will guide you (step by step) to build a full business Android app from login screen to the payment screen

But at first, It will teach you Kotlin programming language from scratch, then you will learn how to create web services using PHP. Next you will learn how to use Kotlin in android app development

This course has many reach topics like Volley, Picasso and Recycler View

It's divided into five sections:
Kotlin Basics
PHP and MySQL
Android app development using Kotlin
Build the full project
Bonus Videos

More info - https://www.udemy.com/android-e-commerce-app-using-kotlin-php-and-paypal-api