App Inventor is a visual, blocks-based programming language and online platform for creating mobile apps for Android devices. It was developed by MIT’s Media Lab and is now maintained by the Massachusetts Institute of Technology (MIT). It allows users with little or no programming experience to create their own mobile apps by dragging and dropping visual blocks that represent programming concepts. App Inventor is also open-source, which means that anyone can access, modify, and distribute the software. It is intended to help educators and students learn programming and is widely used in classrooms and educational institutions.
It is possible to create an SMS application using App Inventor. To do this, you would first need to design the user interface of the SMS application using the built-in components such as Buttons, TextBoxes, and PhoneNumberPicker. You would then need to create event handlers for the various buttons and components using blocks. These event handlers would specify the behavior of the SMS application, such as sending an SMS message to a selected recipient.
To create the interface, you can use a PhoneNumberPicker component, which allows users to select a recipient from their device’s contact list, a TextBox for the message and a Button to trigger the sending of the message. You can also add additional components such as a Label to show the character count, or a button to clear the message.
Once the interface is set, you can proceed to set up the event handlers to make the SMS application functional. You can use blocks to specify the behavior of the application when the buttons are pressed. For example, when the user presses the “Send” button, an event handler would be triggered that would gather the information entered in the TextBox and PhoneNumberPicker component, and use the built-in SMS component to send the message to the selected recipient.
It’s important to note that, App Inventor uses the built-in SMS functionality of the device, so the user needs to have a working SMS plan with their carrier. Additionally, the user will be prompted with a confirmation message before sending the SMS, this is a security measure to prevent accidental sending of messages.
In this tutorial we will create an application named ‘SMS’ with App Inventor that sends an SMS from a mobile application to a phone number.
We propose to create the design of the application, with the following visual:
To program the application, App Inventor proposes to use The Space Blocks which allows to create a program in the form of a block diagram. Very simple to use but requiring some programming logic.
Here is the SMS program realized in the Blocks area of the Inventor App: