Tap the Share button (it looks like a square with an arrow pointing out of it) at the bottom of the screen.
Scroll down and tap "Add to Home Screen."
You'll be prompted to choose a name for the homescreen icon. You can keep it as "Testwords" or customize it.
Tap "Add" in the top-right corner.
You'll now see an icon for Testwords on your home screen!
Tap the Menu button (three dots in the upper-right corner).
You will see an option "Install App", or "Add to Home screen" or similar. Select it.
You'll now see an app icon for Testwords on your screen!