Android Hacks

425 Articles

Going Native With Android’s Native Development Kit

September 15, 2025 by 8 Comments

Originally Android apps were only developed in Java, targeting the Dalvik Java Virtual Machine (JVM) and its associated environment. Compared to platforms like iOS with Objective-C, which is just C with Smalltalk uncomfortably crammed into it, an obvious problem here is that any JVM will significantly cripple performance, both due to a lack of direct hardware access and the garbage-collector that makes real-time applications such as games effectively impossible. There is also the issue that there is a lot more existing code written in languages like C and C++, with not a lot of enthusiasm among companies for porting existing codebases to Java, or the mostly Android-specific Kotlin.

The solution here was the Native Development Kit (NDK), which was introduced in 2009 and provides a sandboxed environment that native binaries can run in. The limitations here are mostly due to many standard APIs from a GNU/Linux or BSD environment not being present in Android/Linux, along with the use of the minimalistic Bionic C library and APIs that require a detour via the JVM rather than having it available via the NDK.

Despite these issues, using the NDK can still save a lot of time and allows for the sharing of mostly the same codebase between Android, desktop Linux, BSD and Windows.

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A Look At Not An Android Emulator

September 10, 2025 by 14 Comments

Recently, Linux has been rising in desktop popularity in no small part to the work on WINE and Proton. But for some, the year of the Linux desktop is not enough, and the goal is now for the year of the Linux phone. To that end, an Android Linux translation layer called Android Translation Layer (we never said developers were good at naming) has emerged for those running Linux on their phones.

Android Translation Layer (ATL) is still in very early days, and likely as not, remains unpackaged on your distro of choice. Fortunately, a workaround is running an Alpine Linux container with graphics pass through via a tool like Distrobox or Toolbox. Because of the Alpine derived mobile distribution postmarketOS, ATL is packaged in the Alpine repos.

In many ways, running Android apps on Linux is much easier then Windows apps. Because Android apps are architecture independent, hardware emulation is unnecessary. With such similar kernels, on paper at least, Android software should run with minimal effort on Linux. Most of what ATL provides is a Linux/Android hardware abstraction layer glue to ensure Android system calls make their way to the Linux kernel.

Of course, there is a lot more to running Android apps, and the team is working to implement the countless Android system APIs in ATL. For now, older Android apps such as Angry Birds have the best support. Much like WINE, ATL will likely devolve into a game of wack-a-mole where developers implement fresh translation code as new APIs emerge and app updates break. Still, WINE is a wildly successful project, and we hope to see ATL grow likewise!

If you want to get your Android phone to talk to Linux, make sure to check out this hack next! 

The Android Linux Commander

September 9, 2025 by 7 Comments

Last time, I described how to write a simple Android app and get it talking to your code on Linux. So, of course, we need an example. Since I’ve been on something of a macropad kick lately, I decided to write a toolkit for building your own macropad using App Inventor and any sort of Linux tools you like.

I mentioned there is a server. I wrote some very basic code to exchange data with the Android device on the Linux side. The protocol is simple:

  • All messages to the ordinary Linux start with >
  • All messages to the Android device start with <
  • All messages end with a carriage return

Security

You can build the server so that it can execute arbitrary commands. Since some people will doubtlessly be upset about that, the server can also have a restrictive set of numbered commands. You can also allow those commands to take arguments or disallow them, but you have to rebuild the server with your options set.

There is a handshake at the start of communications where Android sends “>.” and the server responds “<.” to allow synchronization and any resetting to occur. Sending “>#x” runs a numbered command (where x is an integer) which could have arguments like “>#20~/todo.txt” for example, or, with no arguments, “>#20” if you just want to run the command.

If the server allows it, you can also just send an entire command line using “>>” as in: “>>vi ~/todo.txt” to start a vi session.

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Bootstrapping Android Development: A Survival Guide

September 4, 2025 by 23 Comments

Developing Android applications seems like it should be fairly straightforward if you believe the glossy marketing by Google and others. It’s certainly possible to just follow the well-trodden path, use existing templates and example code – or even use one of those WYSIWYG app generators – to create something passable that should work okay for a range of common applications. That’s a far cry from learning general Android development, of course.

The process has changed somewhat over the years, especially with the big move from the Eclipse-based IDE with the Android Development Tools (ADT) plugin, to today’s Jetbrains IntelliJ IDEA-based Android Studio. It’s fortunately still possible to download just the command-line tools to obtain the SDK components without needing the Google-blessed IDE. Using the CLI tools it’s not only possible to use your preferred code editor, but also integrate with IDEs that provide an alternate Android development path, such as Qt with its Qt Creator IDE.

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The Browser Wasn’t Enough, Google Wants To Control All Your Software

August 28, 2025 by 170 Comments

A few days ago we brought you word that Google was looking to crack down on “sideloaded” Android applications. That is, software packages installed from outside of the mobile operating system’s official repository. Unsurprisingly, a number of readers were outraged at the proposed changes. Android’s open nature, at least in comparison to other mobile operating systems, is what attracted many users to it in the first place. Seeing the platform slowly move towards its own walled garden approach is concerning, especially as it leaves the fate of popular services such as the F-Droid free and open source software (FOSS) repository in question.

But for those who’ve been keeping and eye out for such things, this latest move by Google to throw their weight around isn’t exactly unexpected. They had the goodwill of the community when they decided to develop an open source browser engine to keep the likes of Microsoft from taking over the Internet and dictating the rules, but now Google has arguably become exactly what they once set out to destroy.

Today they essentially control the Internet, at least as the average person sees it, they control 72% of the mobile phone OS market, and now they want to firm up their already outsized control which apps get installed on your phone. The only question is whether or not we let them get away with it.

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The Android Bluetooth Connection

August 27, 2025 by 14 Comments

Suppose someone came to talk to you and said, “I need your help. I have a Raspberry Pi-based robot and I want to develop a custom Android app to control it.” If you are like me, you’ll think about having to get the Android developer tools updated, and you’ll wonder if you remember exactly how to sign a manifest. Not an appealing thought. Sure, you can buy things off the shelf that make it easier, but then it isn’t custom, and you have to accept how it works. But it turns out that for simple things, you can use an old Google Labs project that is, surprisingly, still active and works well: MIT’s App Inventor — which, unfortunately, should have the acronym AI, but I’ll just call it Inventor to avoid confusion.

What’s Inventor? It lives in your browser. You lay out a fake phone screen using drag and drop, much like you’d use QT Designer or Visual Basic. You can switch views and attach actions using a block language sort of like Scratch. You can debug in an emulator or on your live phone wirelessly. Then, when you are ready, you can drop an APK file ready for people to download. Do you prefer an iPhone? There’s some support for it, although that’s not as mature. In particular, it appears that you can’t easily share an iPhone app with others.

Is it perfect? No, there are some quirks. But it works well and, with a little patience, can make amazingly good apps. Are they as efficient as some handcrafted masterpiece? Probably not. Does it matter? Probably not. I think it gets a bad rep because of the colorful blocks. Surely it’s made for kids. Well, honestly, it is. But it does a fine job, and just like TinkerCad or Lego, it is simple enough for kids, but you can use it to do some pretty amazing things.

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Google Will Require Developer Verification Even For Sideloading

August 26, 2025 by 115 Comments

Do you like writing software for Android, perhaps even sideload the occasional APK onto your Android device? In that case some big changes are heading your way, with Google announcing that they will soon require developer verification for all applications installed on certified Android devices – meaning basically every mainstream device. Those of us who have distributed Android apps via the Google app store will have noticed this change already, with developer verification in the form of sending in a scan of your government ID now mandatory, along with providing your contact information.

What this latest change thus effectively seems to imply is that workarounds like sideloading or using alternative app stores, like F-Droid, will no longer suffice to escape these verification demands. According to the Google blog post, these changes will be trialed starting in October of 2025, with developer verification becoming ‘available’ to all developers in March of 2026, followed by Google-blessed Android devices in Brazil, Indonesia, Thailand and Singapore becoming the first to require this verification starting in September of 2026.

Google expects that this system will be rolled out globally starting in 2027, meaning that every Google-blessed Android device will maintain a whitelist of ‘verified developers’, not unlike the locked-down Apple mobile ecosystem. Although Google’s claim is that this is for ‘security’, it does not prevent the regular practice of scammers buying up existing – verified – developer accounts, nor does it harden Android against unscrupulous apps. More likely is that this will wipe out Android as an actual alternative to Apple’s mobile OS offerings, especially for the hobbyist and open source developer.