MIT App Inventor: Build AI and IoT Apps with Raspberry Pi and ESP32
“The hardware-oriented chapters show how smartphone apps can communicate with Raspberry Pi Pico W, Raspberry Pi 5, Arduino UNO R4 WiFi, and ESP32 systems using Wi-Fi, Bluetooth Classic, and Bluetooth BLE.”
Category Archives: General
URL Change as of January 8 2026
Learn2C.org is still an active web address for this web site – but I have since begun hosting this content on my own server at https://coldstreams.com/appinventor
At some point I may choose to discontinue using Learn2C.org and use my own server instead, which is now getting more visits than Learn2C.org.
The appinventor.pevest.com URL has been changed to https:/coldstreams.com/appinventor
The original appinventor.pevest.com URL will redirect to the new URL – however, if using a default https: prefix, you may receive an error that the URL is not secure.
That’s true, because I did not renew the SSL certificate for the original appinventor.pevest.com URL.
But if you click through, you’ll end up at https://coldstreams.com/appinventor– which has the proper SSL certificate.
Android hackers writing malware attack apps using App Inventor
There is no problem with using App Inventor to write your own apps and share them with others. The problem is that App Inventor makes it easy to write any app – and malware authors have begun to use App Inventor to create apps that are malware and might do bad things.
“App Inventor doesn’t give malicious apps any special powers nor access to exotic exploits to attack your phone. But it does make the production of Trojanized apps enormously easy. With only a basic understanding of Android programming, an attacker can churn out tons of malicious apps. More apps means more confusion, and more opportunities for attack.”
Source: Mobile Threat Monday: Android Attackers Use App Inventor for Evil | PCMag
2/3rds of programming projects expected to use “low code” tools by 2025
App Inventor is a “low code”, visual software development tool. Such “drag and drop” programming tools enable non-programmers (and programmers) to create many types of applications without the details of traditional programming code.
This leads to an important issue – will less trained/less experienced programmers inadvertently introduce security problems in their applications?
Gartner predicts that by the end of 2025, over 65% of development projects will use low-code builders. The field of low-code continues to expand. But what security implications does low-code introduce? Low-code refers to tools that enable application construction using visual programming models. Adopting drag-and-drop components instead of traditional code, no-code and low-code platforms enables non-technical folks to construct their own workflows without as much help from IT. Yet, handing power to citizen developers with less security training can be risky. Plus, low-code platforms may hold compromised propriety libraries or leverage APIs that may unknowingly expose sensitive data to the outside world. There’s also the possibility that low-code could increase shadow IT if not governed well.
Apologies for lack of updates
Sorry for the lack of updates and posts to this web site. I have had a lot going on – and right now, we are in process of moving across the state. Eventually things will be settled down. I completed several interesting App Inventor projects but have lacked time to get them posted here. Hang in there – I intend to be back!
MIT App Inventor for iOS Enters Beta Testing
MIT has announced that the App Inventor for iOS (Apple iPhone and iPad) has entered beta testing. The Beta test program is currently limited, but is expected to expand in the summer, with a public release next summer.
Source: MIT App Inventor for iOS Enters Beta Testing | Explore MIT App Inventor
Learn2c.org web site has a new, cleaner and simpler look
I have redesigned the Learn2c.org web site to feature this clean and simple look, with less clutter than I had on the prior design. Do not be alarmed – its the same web site as before!
The following is a cross-post from my older web site on App Inventor:
This web site – appinventor.pevest.com – is no longer the primary web site for our App Inventor tutorials. However, that web site will remain there indefinitely as many people link to it, including search engines and my own e-books 🙂
The new, short and easy to remember URL is Learn2C.org as in “Learn 2 Code”
Unfortunately, for reasons I will not get into, it is not possible to integrate the two web sites together. So appinventor.pevest.com will remain “as is”, and Learn2C.org is the primary focus point.
I am looking into having Learn2C automatically cross post to the appinventor.pevest.com web site but that has not yet been implemented. But I’d like to do that for those that already follow the appinventor.pevest.com web site.
My apologies for not doing a lot of updates during 2018. I have already written some new code examples (Bluetooth LE anyone?) and am working on more in that area. These tutorials will appear once I have completed the entire series of example programs. There are also other items in the works that I cannot talk about yet.
The most popular programming languages
There are many surveys of programming language popularity. Many of the popular surveys have problems with the survey methodology such that they likely produce erroneous estimates of programming language popularity. For example, one survey looks at how many times each programming language is looked up on Internet search systems.
The chart, below, comes from GitHub and bases popularity on the number of “pull requests” that are made to the GitHub software repository. Using this method, JavaScript is the most popular programming language, followed by Python, Java, Ruby and PHP.
Python has become a standard for use by non-computer science students. Whether your college studies be in mechanical engineering or geology, there is a good chance you will learn Python for data analysis projects.
Java is now an old programming language, but still used especially for Android programming. It’s popularity for desktop applications is starting to diminish.
Ruby become popular about ten years ago. Ruby is based on a concept of “frameworks” that provide pre-made program skeletons which you adapt to make your own application. Ruby is very popular for quickly creating web-based applications.
PHP pre-dates Ruby – PHP is a script language that runs on the server side of a web application. PHP is very easy to learn and couples easily with MySQL databases, making the combination a great solution for web-based, database-backed applications.
Finally we get to the “C” derived languages including C, C++ and Microsoft’s cousin C# (a very powerful language with great development tools.). C dates back to about 1970 or so.
C++ was developed in the 1980s and added object oriented programming to C and has since expanded in many ways. C and C++ are commonly “compiled” into machine instructions for each CPU and are used for high performance applications, including operating systems, video games and media applications.
C# has features resembling Java and C++ – but in a more modern design. In some ways, C# is where some wish C++ had gone 🙂
Interested in JavaScript programming?
A follow up to my earlier post asking about interest in other programming languages.
How about JavaScript? JavaScript is widely used in web development, can be programmed with a text editor and tested with a browser – you do not need to download and install development software.
Another plus, if you do choose to download an Integrated Development Environment, you can then package your JavaScript apps within PhoneGap and run them on Android and iOS devices. Thus, JavaScript is another way to write apps for Android (and iOS) that goes beyond App Inventor.
My thinking is this topic could be of interest to those wishing to leverage their App Inventor programming on to other types of programming. The idea would be to create tutorials that leverage what you know about App Inventor (hopefully!) and translate that into JavaScript.
For now, this is just an idea. Looking for feedback!
Learn Javascript programming?
If you have already learned App Inventor programming, what new things would you be interested in learning?
For example, would you be interested in Javascript tutorials that help you translate your App Inventor skills into programming Javascript or some other programming language? Possibly for mobile apps but perhaps for desktop apps or web apps?
What App Inventor features or techniques would you like to learn about for App Inventor? I do not write custom apps here but instead try to identify generic features and methods that might be useful to know across many different types of apps.
Leave a comment with your thoughts. Thanks!
App Inventor 2 - Learn to Code (Learn2c.org) 