# Hello World

## Connecting your computer to a tablet or phone

The ideal way of building Apps using the MIT App Inventor platform is building your App on your computer, desktop or laptop, and testing it in real-time on your tablet or phone. 

{% hint style="danger" %}
Your computer and device must be on the same network for live testing to work. Some network configurations may prevent live testing. Please check with your network administrator if you experience an issue.
{% endhint %}

![](https://lh4.googleusercontent.com/S-uHr5INospeKDXjWZLqbzkYZQI4n8iG38aflTxo-HyV0znuLNcsRtHdBY_tWWWlZ_SSAF7B2Gb4tSfI0K29Tp3M8n_51_zOAj0ptgFiERvx8cP2ZoEkaL536UOe1c7Vo7n_gmcr)

## MIT AI2 Companion

On your Android device, open the Play Store App and search for MIT AI2 Companion from the MIT Center for Mobile Learning.  Click on Install.

![](https://lh5.googleusercontent.com/8QO9iLD5YepAzGV0ezGNuvE3ir2zdM48xI7ahWBG5ftCvzJbOIwP6REr1HrjCDqUl2jJ7yo6vCNLeoSasAZc7XnV4tzvsv6h35kh-Al_58xfShM2cXP-SVvZACOrDAA-EMCspIgN)

## **MIT App Inventor website**

Using Chrome or Firefox, open the MIT App Inventor website <https://appinventor.mit.edu>

Click on **Create Apps!** and sign in with your Google account.

{% embed url="<https://appinventor.mit.edu/>" %}

## Hello World Project

Click on **Start new project.**

![](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-Lxy2_SwSud_zsI_gAWP%2F-Lxy4zabvq7O_S1Kyi8m%2Fimage.png?alt=media\&token=0f161864-540f-446a-a3cc-3baec32afb21)

### Project name

Name the project **HelloWorld**

{% hint style="info" %}
Project names are case sensitive.
{% endhint %}

![](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-Lxy2_SwSud_zsI_gAWP%2F-Lxy5EaxCClNszY3uwRm%2Fimage.png?alt=media\&token=bce2b58a-b873-4243-a285-80db19c25f1d)

{% hint style="warning" %}
Project names cannot contain spaces.
{% endhint %}

### Writing your HelloWorld App

![](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-Lxy952J1c_d4Lg6J81J%2F-Lxy9kLxHGMv7yYIlQew%2Fimage.png?alt=media\&token=fb14bd47-35be-4a1e-8b75-b6ff2c443a7b)

### Drag a Label onto the Screen

![](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-LxyA2_9lRCJLxmjqtpB%2F-LxyAMHpZPyodWlIJRtK%2Fimage.png?alt=media\&token=b6312a82-48ff-48ba-a5b2-91310e03323a)

### Properties

Change the text to Hello World!

![Properties -> Text](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-LxyAe8Ume-WCCKfCMXG%2F-LxzP4fZ9aW5f-SSn1pa%2Fimage.png?alt=media\&token=4a082a0a-785b-47cb-9654-48d039d48d95)

![](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-LxyAe8Ume-WCCKfCMXG%2F-LxzPDULS4sl6lcLmP0p%2Fimage.png?alt=media\&token=2c397387-b941-4ab9-aeb9-1367cb00ec64)

You'll notice the text on the screen updates to Hello World!

## Connect to AI Companion

Click on Connect and select AI Companion.

![](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-LxzRGguDLP1kXl4gL4F%2F-LxzS3NGTaC23jwxrSLp%2Fimage.png?alt=media\&token=0cedc97a-ab21-459d-86e7-48353361d6b5)

A popup window appear with a QR code and a 6 letter code to connect your App to your device. On your device, you can either scan the QR or type in the code.&#x20;

{% hint style="info" %}
Scanning the code much faster than trying to type it in.
{% endhint %}

![](https://138613926-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LhYBl_iAfyX1BvdXUa_%2F-LxzRGguDLP1kXl4gL4F%2F-LxzSDzjwoh5ftEHXTtH%2Fimage.png?alt=media\&token=0f4ba8ab-ce2a-4c10-967c-9eab71933002)

![](https://lh4.googleusercontent.com/tcJfROUr7pUVWz3nEEwxVqSyCjbZBn3gNCELW6bVPqJnzV6NVtih6Tfonlb9L8wzjLr-QkwV26YQK-KyOR9JJcjuhHkf9U_YcVGDNRgtJVPvVBO3b_XkzTqk4yDMZdSF6J0AQen7)

![](https://lh3.googleusercontent.com/zPv9HdjvPNO7s2r63fJgTN8Q3j6m6_Zu7Qwq2nFwke4JnOyhc9cNaKzq--RD6JNjT0cWkpuBBQ-65GyjRO6LTdpvsEBUKxTnFoI2duZW41Lw2vMX-caAmacyNxZ1tNzXBWpmmHh9)

![](https://lh4.googleusercontent.com/R1JYFV1lrVlDPbWmE9z94X-DWi_DbbtcXQz1kaiRMOtui0kTKJWEWA23VNlZUTbSvALoTtd9beqqcMEBU4ORbqxuKxv3LMGyy1LyN0JN4FZIt1rwEydxUy4etmtcLft1ZkyJgP2K)

### Screencast Recap

{% embed url="<https://www.youtube.com/watch?v=wOVdaWlZSkE&feature=youtu.be>" %}

### Live Testing Success

If all goes well, you’ll see Hello World! on your device’s screen! Any changes or updates to your program that you do on the MIT App Inventor website will appear on your device instantly.

![](https://lh4.googleusercontent.com/qM1qfPn3q2OWdUYUR3BaFZTH2G-DPG0eQZhUohYDNoMOBIqjI05NBjiP-8H5EXTNpiyWpGFxFH8awbZYPN7zUlqz88VpsPmk29SgL_NqgATsPoLXsfv84Y1uUjlQAAbR8OB7rXCQ)