That Is your smartphone game finished! Well done! Now you can make any final changes to customise the UI and choose Projects > Save project from the top menu to save the current form of your game.
If you wish, you can share your game in an executable form (.apk) that can be installed on a phone, or in source code form (.aia) that can be loaded into App Inventor.
To share the source code:
Choose Projects > My projects from the top menu to see a list of your projects. Select the project you wish to share by checking the box next to it. Choose Projects > Export selected project (.aia) to my computer to export the source code for your project. The source code is downloaded in .aia file format.
You can now send the file to a friend and they can open it with App Inventor to play the game and even remix the code. Choose Project > Import project (.aia) from my computer to open the source code of someone else’s game.
To share the game in an executable form:
Package the game (.apk file) by opening the project in the Designer editor. Choose Build > App (save .apk to my computer) from the top menu to download the .apk file. The option App (provide QR code for .apk) produces a scannable QR code that will download the game for two hours. You can share this code with others, but they have to use it within two hours from when you generate it.
Once the build completes, you can send the game (.apk file) to your friends who can install it by opening the file on their phone.