Introduction to Extension Development

As you will know, extensions are components which extend the functionality in App Inventor.

Sites such as Thunkable and Appy builder are what's referred to as a distribution of App Inventor, because App Inventor is open source software anyone can take the code and create their own distribution easily.

Many of the available distributions offer extra features which aren't available in App Inventor, which attracts more people to use other distributions instead. Most of the other distributions, however, are more commercially focused and therefore don't offer their code as open source.

When you create an extension for App Inventor you are creating an extension that works across all distributions as it's all based on the same platform.

Extensions can only be non-visible components at this point in time, what this means is that components you create will generally not be able to draw anything on the screen, there are some exceptions to this where you can invoke a visible component (like a progress bar or dialog), but technically your extension is still not considered visible.

Despite some limitations, extensions can be extremely powerful tools to enable advanced features in your mobile applications, to see a complete list of extensions other people have made checkout the index page on the Thunkable Community.

In the next lesson, we'll look at what you need before you can start creating extensions so stay tuned for the next lesson in the series by following me on Google+, Blogger, or my RSS Feed these lessons will be posted weekly until I run out of scheduled content.

Start Lesson 2