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.”
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.
Low-Code Software Development
What is Low-Code? – by Sophie Becker – Technically (substack.com)
Read the linked article.
Way back in my college days, we learned to program in everything from assembly language up through “high level” programming languages. Some of us even learned to enter boot strap code using front panel switches to enter machine code as bit patterns on a console!
And then the hard code folks who said their programming language was solder (author Terry Pratchett, for example, or Bob Pease, or Steve Ciarcia).
Today, programming is simplified – tools like App Inventor illustrate this by using “drag and drop” programming methods, assembling programs from components, rather than typing in programing instructions.
Low Code does not necessarily divorce oneself from understanding programming concepts – but it enables the rapid construction of many functions – from user interfaces to underlying algorithms.
AI-based systems introduce a new level of automated code assembly. Go to Chat GPT, for example, and ask it to implement a sorting algorithm in Python – and sure enough, it will generates the source code in Python.
Two or three decades ago, the typical output of a software developer was likely to be a few hundred lines of code per day (at best, after integration, testing, and future modifications before final ship). New tools likely increase this by an order of magnitude and more!
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.
Access to example source code files may be offline – December 2019
My Internet service provider informed its customers this morning that they will be discontinuing their web site hosting and email services in February of 2020. This means my appinventor.pevest.com web site, which has some of the example source code files, needs to be transferred to a new web service. During that transfer, access to some of the source files will be offline for a bit.
This will especially affect access to the sample source files featured in my App Inventor e-books.
I have 5 web sites that I need to move to a new server and the transfer process is somewhat complex. I do not yet know when this transfer will take place.
This post is an advance warning that this will be happening and hopefully file access will not be offline for long – when the transfer occurs. At this time, I have no date yet for when this process will be undertaken.
Source code downlinks fixed
Two readers alerted me to problems downloading the source code on the Downloads page on this web site, and the source code for my book on App Inventor graphics and animation.
A software update on the server appears to have changed how some default file directories were appended to filenames.
The problem appears to now be fixed. Thank you very much for letting me know of this problem – let me know in comments if you encounter any further problems with the downloads.
Ed
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.
App Inventor 2 - Learn to Code (Learn2c.org) 