My motivation described in this SO question, is to take screenshots that are saved as .jpg so I can add EXIF data to them. Android's default method of taking screenshots (power button+volume down) saves screenshots as .png for which there is no EXIF data.
I saw this app called Button Mapper that lets you customize what happens when a certain button is pressed. So for example, you can make it so that when you double press the volume down key, it lets you see the apps that are open.
How can I achieve something like this? Any tutorial would be good.
