To add Scrabble Solver to your Android device tap the menu button (three dots, usually at the top right of the screen):
Then click the download button seen in the middle here:
Or tap Add to Homescreen:
Scrabble Solver will then appear with your other Apps.
In Samsung Internet tap the download icon in the top right:
Then tap Install:
Alternatively tap the menu button in the bottom right:
To exit the Scrabble Solver App on your Android Device tap the Home Button at the bottom of your screen.
Depending on the type of Android device you have it may be necessary to Swipe Up from the bottom of the screen to show the Home Button.
There is more on how to display the Home Button in this Google Support article.
You can also encourage the Home Button to appear by tapping here.