1. Setup
This page describes how to setup your computer and phone for building apps
with App Inventor.
1. Login. Open a browser to beta.appinventor.mit.edu. Login with your Google
account.
2. Download the App Inventor software.
• In App Inventor, Click on the Learn link, then the Setup link, and setup
your computer.
• Most computers have Java on them already, so for now ignore that step.
• Instead, go straight to Install the App Inventor Setup Software
instructions and follow the link for the type of computer you have.
o If you have a MAC: Download the .dmg file and double click it. It
may start the install process automatically. If not, look on your
desktop and you'll see a mounted disk. Click it, then double click on
the .pkg file within it. This will start the install process. After
installation completes, you are ready to go.
3. Create a new project and open the blocks editor
• Back in App Inventor (beta.appinventor.mit.edu in your browser) choose
the New button on the far left to create a new project. Enter a name for the
project. This will open the Component Designer. This is where you'll
show how the app will look.
• In the Component Designer, click on Open Blocks Editor. A dialog
should appear asking if you want to open or save a file named
appinventorForAndroidCodeblocks.jnlp. If one option is to open it with
Java Web Start, perfect, do so. The process will take up to a minute, so
don't get impatient. If after a minute nothing has happened, look in your
downloads folder to see if the file is there, and double click it.
If the system doesn't ask you to open with Java Web Start, you probably
need to configure your system with Java (go back to the Learn | Setup
screen).
• The blocks editor is where you'll program the behavior of your app, e.g.
what happens when the user clicks on a button.
4. Open an emulator
• Once you've successfully opened the blocks editor, click on New
Emulator. Click OK on the dialog that appears. In about a minute, an
emulator (an on-screen phone) will appear.
5. Now you're ready to build an app. Most people start with Hello Purr, an app in
which touching the phone (or clicking the emulator) causes a cat to meow.

2. Hello Purr (pdf)