Write an Android application

My android compiler and development environment is Android Studio 1.4.1. My Phone is a Samsung SGH-T599 with T-Mobile, but used last with Ultra Mobile. It is running android version 4.1.2 The phone has no phone service so it can only use the internet through the Wi-Fi. What I want is to modify the [login to view URL] program which is a zip of the android app I tried to run through available online tutorial to connect to the internet through phone service data (before but I was not successful) and also now with Wi-Fi, and I was still not successful, so that it can connect through either data phone service (when I have one) and Wi-Fi that I can currently connect to the internet through. I want you to write a tutorial or not of what changes you made to the project files or programmatically to make the InternetPTest project work to connect to the internet (through both Wi-Fi and phone data). Also, I want you to create a data file as well so I can see how to read and write a data file in a android app. Put a tutorial or walk through of how you are able to read and write a data file in the returned file you send back as completion of this upwork project. Instead of a written tutorial, you can use a video tutorial if that is easier. If you have any question related to the project, let me know in your response.