Locate the easiest to use game app development software that is free and known to be reliable. For this application, use Google APP Inventor.
Download APP Inventor to your computer from the Google APP Inventor website. Follow the instructions to install APP Inventor.
Start APP Inventor and create a new project. Connect your smartphone to your computer's USB port.
Use the sound, picture, text and touch button components in the APP Inventor tool box to create a simple game app. Follow the beginner's tutorial on the APP Inventor website to see how you drag and drop each of these components to make a simple game app.
Click the download option in APP Inventor to download the game app you created to your phone. Test the game on your phone.