RFIDtools: an Android app for Proxmark3 and other NFC hardware

Putting research RFID hardware in your hand

RFIDtools is an Android application for use with the Proxmark3 RDV4 and the blueshark addon, and the repository description calls it the RRG Android app for use with Proxmark3 RDV4 and the blueshark addon. The list of supported devices is what defines the scope. The Proxmark3 sits alongside a generic NFC reader, the ACS ACR-122u, the Chameleon Mini and the PN532, and a second table lists PN53X derived devices that are marked as still being tested, namely the NXP PN533, the NXP PN531, the Sony PN531, the SCM SCL3711, the SCM SCL3712 and the Sony RCS360. The point of the project is portability of the interface rather than new radio work. A Proxmark3 is a device that normally wants a laptop and a terminal, and this app puts the tag operations on a phone you already carry, with an abstracted user interface for read and write actions. The audience is an RFID researcher or a security tester who wants field capability, and the app is distributed on the Google Play Store under the package com.rfidresearchgroup.rfidtools as well as through GitHub releases.

The native layer: JNI, CMake and a local socket

The core implementation section of the README is where the engineering is described, and it is unusually blunt about the shape of the system. Communication is done with LocalSocket and LocalServerSocket on Android, which map onto the Linux socket API and the abstract namespace. The build is Gradle and CMake together, and the architectural pattern is MVP, a model, view and presenter arrangement. All of the libraries are compiled into shared objects named libxxx.so, with JNI and the NDK as the bridge from Java down to C, and the README is explicit that this is not a Linux executable, while the Proxmark3 client is a Linux executable. The repository layout matches that description, with separate directories for the pieces: libpm3 for the Proxmark3 client, libnfc for the PN532 family, libcml for the Chameleon Mini, libcrapto1 for the ACR-122u, plus libflasher, libmfkey for MIFARE key handling, libtag, libcom and libutils. There is also an apprts directory for the application itself, and terminal-emulator, terminal-view and termux-app directories, which is the embedded terminal that the external executables are run inside.

The reconstruction: dropping the bundled toolchains

The README describes the current work as a second crazy reconstruction, a phrase that is easy to read past and is in fact the most important operational fact about the project. Five items are listed. The user interface is redesigned, with a simplified page hierarchy and simplified operation logic. The strong dependency on the Proxmark3 repository is discarded in favour of the external Proxmark3 executable and its resources, and the strong dependency on the PN53X tools, mfcuk and mfoc among them, is likewise discarded in favour of external executables. Communication is to be optimised to reduce delay, and support for some Bluetooth low energy devices is to be added. The reason this matters is the warning attached to the list, that before the reconstruction is completed the whole project may have big problems such as build failure or crashes at runtime, and that it should take some time because one person is doing the fighting alone. That is a candid statement of the state of the code, and it changes how the release history should be read. Moving from bundled libraries to external executables is a sound direction, because it stops the app shipping and patching copies of third party tools, but it also means the app now depends on the user having those executables available on the device, which is a distribution problem the old arrangement did not have.

Building it: Android Studio, CMake and the NDK

The build documentation is brief, which is consistent with a project aimed at people who already work with Android native code. The development tools are listed as the IDE Android Studio, CMake at 3.10 or newer and the NDK at 20.0.5594570 or newer, and the build steps are to fetch the source from GitHub and then open the project in Android Studio.

git clone https://github.com/xianglin1998/RFIDtools RFIDtools

After the clone, the README says to open the RFIDtools directory with Android Studio, which tells you the Gradle and CMake files at the root are what the IDE drives, consistent with the note that the build is Gradle and CMake together. The repository also carries gradlew and gradlew.bat wrappers, a gradle.properties file, a settings.gradle file and an import-summary.txt, which is the kind of artefact left behind when a project was imported into a different build system. For anyone with an existing Android native background this is a familiar setup, and the older version of the source, the xianglin1998 repository named in the clone command, is presumably the origin of the current tree under the RFID Research Group organisation. The binaries in the Play Store and the GitHub releases are the practical route for most people, since compiling the native layer is only worth it if you intend to change it.

Compatibility is a short list of phones, and the README says so

The compatibility section is a list of three devices, and the README invites people to contribute their own findings. The tested phones are the Redmi K20 Pro on MIUI 10 and Android 9, the Redmi K20 on MIUI 10 and Android 9, and the OnePlus 5T on H2OS 5.1.2 and Android 8.1.0. A vendor link points to a site for buying the devices, which tells you the audience these were sourced for, which is Android OnePlus and Xiaomi hardware in the Chinese market rather than the latest flagships. The app is stated to run on a non-rooted phone, and the features section lists that first, which is the practical constraint that matters for an RFID tool, because a rooted phone would simplify the USB and serial handling considerably. The two external dependencies named in the acknowledgements are the Termux terminal and the UsbSerial project, and both appear as directories in the repository, so the serial path is the project's own rather than a stock Android API. That combination, a USB serial library and an embedded terminal, is what allows a Proxmark3 client that is a Linux executable to be run on the device at all, and it is also where the fragility lives, since it depends on the phone's USB host behaviour and on shipping a working shell environment.

Support channels, licensing and a release history that stopped in 2020

The administrative details are straightforward and worth knowing before you install anything. The licence is GPL, and the copyright line reads Copyright DXL 2019, with DXL named as the maintainer and an invitation to contribute. Support is split in a way that is common for small open source projects: issues in the repository are for source code problems, and anything else goes to the email address [email protected]. The update note is a separate document in another repository, and it is linked from the README under the heading for updated notes, which tells you that release and device support information is maintained outside the main tree. The release history is the part that needs interpreting. The listed versions are v1.4.9 from 2020-10-26 with the note that the PM3 resource was updated, v1.4.8 from 2020-08-13 with minimum support for Android 5.1 and direct Proxmark3 working directory support, and v1.4.7 from 2020-07-03 adding Termux and the old console view. So the published builds are five years old while the repository itself is not, since the last push was on 2026-06-25. The honest reading is that the code is being worked on but the tagged artefacts are not, which is exactly the situation the Play Store build, if it is still updated, would resolve.

Editorial conclusion

Adopt RFIDtools if you already own one of the listed readers and want to drive it from an Android phone without a laptop, particularly if you work with the Proxmark3 and are comfortable with the app's own reconstruction caveats. It does not fit a team that needs a maintained release with recent device support, because the newest tagged build is v1.4.9 from 2020-10-26 while the last push was on 2026-06-25, and it does not fit anyone who needs card operations on credentials they are not authorised to read. Before you build it, read the update note linked from the README and try the Google Play build, because the project itself warns of build failures and runtime crashes before the reconstruction is finished.

Frequently asked questions

Official sources

1. Issues
2. License: GPL-3.0
3. README
4. Releases
5. RfidResearchGroup/RFIDtools on GitHub