To acquire: Click 'See inside' and put the script in the sprite 'Button' into your backpack. Then put it in the sprite for the start button, i.e. the button to exit the title screen. To use: When the start button for your project is clicked, it will then respond. The result is stored in the variable 'mobile?’.
This is not 100% accurate as it can be fooled. (See if you can figure it out.) Please give credit if you use this.