A note from the author

This article was updated to account for the recent addition of FBInk to the framework. The addition of FBInk allows for many other kobo devices beyond the original three to be supported.

• If you would like to read the old article, see here
• If you are on the old pre-FBInk version and would like to upgrade, simply download and install the new KoboRoot.tgz

What is RMKit?

RMKit is an open source framework for developing applications for the Remarkable 1 & Remarkable 2 tablets. Support was added for Kobo devices in 2022. RMKit allows you to add additional apps to your eReader, and provides a way to launch them with remux, an application sort of like like KFMon.

Preparation

• Understand that this is a custom modification to your stock firmware. It is unsupported by Kobo and under active development. Under no circumstances shall I or the RMKit developers/contributors be held liable for any bricked, damaged, or unresponsive device.

• Check whether you have a device that is known to be working with RMKit: Kobo Elipsa 2E, Clara HD, or Libra H2O. Any other Kobo device has not been tested, though in theory, any device supported by FBInk (which is the entire Kobo lineup as of the date of this article) should be able to run RMKit.

  Please do try RMKit even if you do not have a known working device. Bug reports on the RMKit Github issues page are always welcome to help improve the project.

  Some known issues according to the dev:

  • On devices with screens that are lower resolution (e.g. Kobo Aura One), the UI may look a bit weird for some applications.
  • On the Kobo Aura One, the swipe input to launch remux is also not working properly.
  • RMKit is not very smart with rotations! If your device supports rotation and RMKit apps are not doing the right thing, please report what happens and what you expect to happen

Download and Installation

• Connect your eReader to a computer or other device for file transfer.

• Head to the RMKit build server and the /master/latest/kobo/ branch to download KoboRoot.tgz

• Place it in the .kobo folder on your eReader – this folder will be hidden by default in Unix systems.

• Eject your device and wait for it to reboot.

Opening Remux

• After installation, swiping up along either side edge of your device anytime will bring up the remux app switcher – this can be a little finnicky, here are some tips (I am using an Elipsa 2E):

  • Make sure to swipe fully from the bottom edge to the top edge

  • Make sure your finger stays entirely on the screen for the whole swipe

  • If the right side is not working, try the left side, or vice versa

  • Tap the screen with your finger once and then swipe

• A video demo by the developer

• Other notes:

  • Remux does not seem to respect orientation – in forced landscape mode swiping on the short side does not work, and nor does swiping along the top/bottom. I am assuming the page turn is conflicting with remux.

  • I find remux to be easiest to open on the home screen, a document/book opened in portrait mode, or a basic notebook. Anywhere with a scrollbar is more difficult as you must swipe in between the scrollbar and the screen edge.

Using Remux

• KoboRoot.tgz will install a few demo applications. To launch an application, press on the entry in remux. The application should launch immediately.

• To return to Nickel (the Kobo operating system), relaunch remux from the application by swiping and click on the Nickel entry.

• Applications can be closed/killed by clicking on their memory usage indicator. The memory indicator should be briefly replaced with killed and then disappear. If an application is not killed, it will remain running in the background alongside Nickel. Note: Nickel cannot be killed, as it is required for your eReader to function.

An image of the remux menu

Adding Applications to Remux

• Reconnect your eReader to a device for file transfer, and open the /.adds/rmkit/bin/apps/ folder. This folder should be new if this is your first time installing any modifications. It is also hidden by default on Unix systems. The demo apps should be in this folder from the initial install.

• Head to the RMKit build server and the /master/latest/kobo/ branch to download the app of your choice, such as harmony. Note that these apps are written for the RM1/RM2 and are not necessarily fully functional on Kobo devices.

• Place your downloaded app(s) in the folder and reboot your device.

• Apps that I have personally tested:

  • harmony

    • Fully functional, including stylus input and eraser support on the Elipsa 2E and touch input on others. Image exports and project files are saved to /.adds/rmkit/data/harmony/

  • dumbskull

    • Fully functional

  • mines

    • Fully functional

  • wordlet

    • Fully functional

  • rpncalc

    • Fully functional

• See the RMKit site for more information on apps.

Disabling Remux

• Reconnect your eReader to a device for file transfer, and delete the file enable_remux in the /.adds/rmkit/ folder.

A Final Note

As mentioned earlier, this under active development, so be prepared for bugs and unexpected behaviour. If you do run into unexpected behavour, feel free to report it on the RMKit Github issues page to help improve the project.

If you want more info, see the MobileRead thread.

Thanks for reading!