Episode: 2118 Title: HPR2118: What is App Inventor? Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr2118/hpr2118.mp3 Transcribed: 2025-10-18 14:32:30 --- This in HPR episode 2,118 entitled What in App Inventor, it is hosted by Acho Daudi and in about 18 minutes long. The summary is an overview of the online free Android app creator. This episode of HPR is brought to you by Ananasthost.com. Get 15% discount on all shared hosting with the offer code HPR15, that's HPR15. Get your web hosting that's honest and fair at Ananasthost.com. Hello everybody, this is Nacho Jordi, real casting one more time for Hacker Public Radio. Today I want to discuss briefly an online application that is quite useful, although somewhat frustrating with its interface sometimes, but nevertheless very interesting and very useful. It is called App Inventor and I think the name itself is at that game, give away, it's an application created originally by the MIT, that it allows you to make applications for Android. Initially, as it was created by a university, its purpose was educational, so it was thought, I think its initial purpose was getting as much people as possible introduced in programming. I guess the folks at Google would also have some kind of interest in getting as many applications in their system as possible, so I think I don't remember it exactly, but I think the project was initially financed or done as a cooperation with Google and now it belongs only to MIT. Google is no longer in charge of that project. App Inventor has been around for a while, its current version is number two. There are a few differences with version number one, which is quite subtlety. It can become a bit important when you're browsing the internet searching for tutorials, because it's not always very clear. Your tendency is to put on the search engine, you usually would put App Inventor tutorial and you might be heading to App Inventor one tutorials, and it's happened to me a couple of times, and you come to a point where you say, hey, this doesn't make sense, this doesn't match with the menus, and in my view, it is not enough. There's not explicitly enough shown when you're reading an App Inventor one tutorial, and like I say, there are differences, so it's better to use App Inventor two in a search term when you look for information on App Inventor. And there's a lot of it, you can find websites, blogs, and YouTube tutorials, and the MIT site itself has a very extensive and very progressive collection of tutorials. You can browse them, you can do them sequentially from the Hello World typical example, or you can search for specific items that are interesting to you. For example, if you want to develop a video game in Android, or you want to do something that involves the GPS, you can go to the specific tutorials that do that. And I like to discuss this resource, this App Inventor, because it's a very good gateway to start Android programming without the overhead of, let's say, the conventional route of having to style the Android Studio and learning their particular version of Java and having to compile the application. This App Inventor simplifies a whole process, and at the same time gives you a lot of power, like I'll discuss in brief, it gives you a lot of options. So yeah, and at the same time, yeah, I thought it was a good idea discussing this App Inventor because I would have loved that someone would have pointed me to this tool, because I remember at the moment when, about a year and a half ago, I decided to, that it would be a nice thing to make my own Android applications just thinking of stuff for myself, like customizing the apps I need. For example, I wanted a chronometer, and I didn't find anything that was 100% the way I wanted. So I sought the internet for a tool, and I didn't find App Inventor until some time later. So maybe that's changed in this year and a half, but at that moment it surprised me that it wasn't a more patent thing. I knew there had to be some kind of entry-level tool as in this App Inventor is, and I wish I would have known it before. So what are the main features of App Inventor? The main thing is that it's a visual language. They have tried to do things as visual as possible. App Inventor has two windows. By the way, it's an online service. It used to be downloadable. But now you can work directly in the browser. I don't remember if the browser version came later or both have always existed online and offline, but the online option is as easy as it gets. You just have to type the www. App Inventor.org. You can make sure the name in any search browser, search engine. And then you go to the page, you give your data to Google as usual. They lead you into your account. And you store your stuff there. And you don't even have to remember to save your project as a thing that really amaze me. At first, it's freaking out. Every change you make is automatically saved. So the moment you're done with your programming session, you just close the browser and you'll find your stuff next time in the point where you left it. So like I said, I'm going to talk about the online version, which is the one that I know better. But I think both from what I can judge out of tutorials, the downloadable version must be very similar. I think it's available. I'm sure it's available for Windows and for Linux. I'm not sure about Mac. If somebody uses Mac, probably I think being something Google related, they might have covered all the bases, but I'm not sure. Well, like I say, the fundamental thing about App Inventor is that they try to be as visual as possible. And everything you do there is you do it with drag and drop. There are two main windows. One is the designer window where you design the appearance, the app is going to have by dragging elements into a mockup cell phone picture in the middle of the screen. And then once you've put those elements, you get them different properties, you know the size, you can say scholars, etc. For example, you can put text fields or buttons, the usual stuff. And then there's another screen in App Inventor. It's called blocks where you define the behavior that those elements are going to have. What do you want your app to do? What do you want to happen when someone clicks the button? And the funny thing about this block screen is called blocks because the App Inventor language, which I don't remember the name, I think it's something like Waba or something like that. Something that's only like Java, but it's not Java. But it is an important thing about App Inventor is that you drag elements which look like puzzle pieces. So you don't have to type the stuff and it has a lot of helpful system of self-completion. But you can just drag and drop the pieces of the programming language. And the way the puzzle shapes are is going to give you a clue of what arguments can you use in a command. That makes it very visual. You can click elements and have a nut ready in no time. And also once you've gone through a couple of tutorials, you just get the knack of it and pretty much the things you don't know you can look for them. And also the App Inventor interface offers you a link to the forum of users where you can find additional information. So like I say, the programming process in App Inventor, you go from the design screen, which is what you see is what you get. So your app is going to look pretty much an approximation. And then there is the blocks screen where you define the behavior of the elements of your app. That's what will make your app tick. And it includes things like databases, for example, something that opens a whole world of possibilities because that allows you to create apps that can store your data and go back to them later. That makes a whole huge difference in the stuff that you can do. And what else? Once you have the app, once you think you have the app ready, there are several things you can do about it, several ways you can test it or get it ready. The App Inventor has the possibility of an emulator and Android emulator appears on screen. I haven't been able to use that option. I don't remember what happened. Maybe it was something I had to download. And I couldn't make it work because the usual dependencies problem, I don't remember. But it was all the options to test my app. It was like the trickiest. So I cannot tell how it about it. I know that it exists and people use it because I've seen it in plenty of videos on YouTube, but I cannot testify how it works. But it has other two options to try your app, leave. And they both are very, very good, very straightforward. One is the so-called companion. The companion is an app that you install in the Android device, you want to test. And then you click in the App Inventor in the computer and it will compile your app and offer you a QR code. So you can scan the QR with your cell phone or your tablet, your Android device. And the app, after scanning, will appear in your device. Not only that, but the changes that you do in the computer will appear in the device almost instantly. So you will see your cell phone starting to crack out of the stuff and then we will show you the effect of your changes. But I found it amazing. It's a way of testing that it's great. You don't have to wait. Other services for Android, you have to compile stuff, wait for them to send it to the email. But there is some time, this one is absolutely great. However, I found that for certain activities, it has limitations. This system at least that will happen to me. I don't know if it's an app inventor or senior or has to do with my configuration. But for example, the services that you want your app to go to our web browser, for example, in my device, sometimes they become sluggish or even they lose connection. So there enters the third option to test your apps, which is simply installing the actual app in your device, which is also the option you will use once you think your app is finished and ready to go. App inventor admits this other option. It can also do it through a QR code or if you have problems with the scanner, it also provides you a numeric code you can type in your device and the app gets installed. So yeah, that's pretty much the overview of what app inventor can do, which is a lot. If you watch the examples, you will see that there's a lot that you can get done with app inventor and I think it's an interesting option. Also, the apps you generate are... I don't remember the whole process but I'm pretty sure that you generate APK files that are ready to go in the Google Play Store. So you can make your apps public for the world to see if you are interested. So if you would like to find a way to make apps in Android and you get nowhere to start, this is definitely worth checking out. So well, I hope some of you will find it interesting and that's all I have for you today. Thank you very much for listening. Bye! This show, like all our shows, was contributed by an HPR listener like yourself. If you ever thought of recording a podcast and click on our contributing to find out how easy it really is. Today's show is released on the create of comments, attribution, share a light, 3.0 license.