Soft Button is an accessibility service for Android devices that lets you easily navigate through your phone's interface using your voice.

To use this service, you will first need to enable it in your device's settings. Then, you can simply speak to navigate through your phone's interface, and it will also let you know what line of code to look for.

The first thing you need to do is go to Settings - Accessibility - Back Home Button and enable it. Then, you can set the Back button to be soft or hard, and you can also set the size of the button.