Setting up my KY-42C flip phone
Warning
If you are using this as a guide and want Play Services on your device, you need to root it first. Unlocking the bootloader (a necessary step to root the device) wipes any data you have on the device. Rooting the device before putting any data on it prevents you from losing any time and work. Please skip to Rooting the phone for information on how to do this.
Please also note that though I talk about Google Fi in this blog, the KY-42C cannot use data on Fi. Please read the results with microG. Google Fi does work with the A202KC, as detailed in my next post.
This guide is confirmed to work on the following devices and build numbers:
I used to maintain a list here. It has since been moved to the Garaho Wiki.
This may have been patched on version 1.090 across the DIGNO 4 lineup (A202KC, A203KC, A204KC, KY-42C, KY-43C). This means it most likely WILL NOT BE POSSIBLE to root the device on 1.090.
Contact me if you can confirm this to be working on any other builds or devices.
Initial setup/installing apps
Upon receiving my Kyocera Digno KY-42C, I changed the language to English, connected the phone to my Wi-Fi and got to work installing F-Droid (a platform for open-source Android apps) and Aurora Store (an alternative Play Store frontend that doesn't require an account or the Play Services). I attempted to download F-Droid via the built-in web browser only to discover that I couldn't download APKs through it. I'm familiar with ADB (Android Debugging Bridge), but it would've been nice to be able to install the stores without a computer. Oh well.
ADB tutorial
This section uses the numpad to navigate which doesn't work on the A202KC. I've added the names of the menus for clarification.
To use ADB, you need to first put the phone in developer mode. Open the Settings app, and hit 8 (or "About phone") to open the "About phone" menu, then hit 8 (or "Build info") again until you get a message that says "You are now a developer!"
Turning on developer mode
You can then go back to the previous menu using the Clear (クリア) button and hit 9 (or "More settings"), then * ("or Developer options") to enter the "Developer options" menu. Scroll down to "USB debugging" and fill the check box.
Turning on USB debugging
Plug the phone in to your computer. Open a terminal window (on Linux and Mac) or a Command Prompt window (on Windows) and navigate to your Downloads folder. Use the following ADB command to install F-Droid:
adb install <filename>.apk
where <filename> is the name of the F-Droid APK file you downloaded previously. In my case, this was just F-Droid.apk. If the phone prompts you to allow ADB access/trust this computer, hit Yes/Accept. Now you can use F-Droid to install other apps, including Aurora Store. Apps show up in the "Tools" menu.
Troubles with some apps
- The Transit app is important for me, so I of course installed it through the Aurora Store. I didn't have any troubles with the app's functionality, other than general slowness, though I noticed my phone's location was more than two miles from my actual location. I fixed this by rooting the phone and installing microG.
- Google Fi wouldn't run without Play Services, which I fixed by rooting and installing microG.
- Google Wallet wouldn't run without Play Services, though microG cannot yet fix this issue. You can track their progress on GitHub.
- microG requires Signature Spoofing, which the default Kyocera ROM isn't capable of. Because of this, I had to root the phone.
Rooting the phone
If you want to skip this tutorial and head straight to the results, go to the results with microG.
I used mtkclient to root my phone. It's specifically made for the chipset used in the KY-42C. Once you've installed mtkclient using their guide, you can skip down to the rooting section.
As of 09-12-2025, I now use the mtkclient derivative in Nixpkgs, the package repository for NixOS. This may also work on other Linux distros, as well as MacOS, if you install using the Nix package manager, but I have only tested it on NixOS. This required me to use superuser permissions (via sudo) to properly connect to the device.
I tried to help another person with mtkclient on Mac - they ended up buying a Thinkpad T470s for 50 euros (insane deal!) to use mtkclient's LiveDVD instead as we had too much trouble on Mac. I read about someone having a similar experience using Windows on Reddit.
I originally used their LiveDVD to access mtkclient (I now use the NixOS package). The shortcuts on the home screen don't work, so I just ran the commands needed inside the /opt/mtkclient (I'm not 100% sure that is accurate, but wherever mtkclient is located) directory. I discovered that the files here were out of date, so in a terminal inside the directory, I ran:
cd ..
rm -r mtkclient
git clone https://github.com/bkerler/mtkclient
cd mtkclient
and continued with the guide.
Make sure you back up the files you get from this process. I put them in my phone's Download folder after the wipe and later backed them up to my computer once I was in my main OS.
Edit: The LiveDVD no longer seems to be up. Phobos has a copy in their tinkering guide. Phobos and I are also considering making a more lightweight, open-source version.
After rooting/microG
Now that the phone had been rooted, I was able to open Magisk, which was the only non-system app on the now-reset device. I needed to enable developer mode and USB debugging again so that I could install LSPosed (download the Zygisk version) with the "Install from storage" button in Magisk's "Modules" tab. To get the file onto the phone, I used
adb push [LSPosed filename] /sdcard/Download/
Before you restart, enable "Zygisk" in Magisk's settings.
Installing LSPosed
After you restart, you should be able to see an LSPosed notification. You can hold the II button to see notifications from anywhere. Press on it to open LSPosed.
Download the FakeGApps APK from its Releases page. Install it with ADB.
adb install [FakeGApps filename]
LSPosed should send a notification about and Xposed module. Click it and enable FakeGApps. We're in the home stretch!
Download F-Droid on your computer and install it using ADB. Navigate to Settings > Repositories in F-Droid and add microG's repository using the first QR code on that website. Install all three - "microG Services," "microG Companion" (for imitating the Play Store) and "microG Services Framework Proxy" (for push notifications from apps). Restart your phone.
microG's repository in F-Droid
Open microG's settings and navigate to "Self-Check." Verify everything under "Signature spoofing support" and "Installed packages" is checked. Click on every entry under "Permissions granted" and allow each one. Click on "Battery optimizations ignored" and ignore... battery optimizations. Go back to the main settings page and enable "Google device registration," "Cloud Messaging" (for push notifications) and "Google SafetyNet." Click on "Play Store services" and enable "Answer license verification requests." You're done! Install Aurora Store using F-Droid if you want apps from the Play Store. If you do this, make sure to blacklist Play Services in Aurora, or else it will try to update microG and fail.
microG's Self-Check page
The results with microG
microG solved a couple of the issues I mentioned before:
- My location is accurate down to the side of the building I'm in!
- The Google Fi app works!
But quite a few remained:
- Google Wallet wants a Play Services update and won't load.
- My Google Contacts and Calendar did not sync with the system apps, and Google's run slowly.
- I solved this with DAVx. To sign in with Google in DAVx, you'll need a newer browser than the default, like Fennec.
- The built-in calendar doesn't read the calendar that DAVx syncs, so another app is needed - but in theory, not the Google app, just one that can read from the system calendar (untested).
- Docomo Phonebook crashes anytime I open a contact. Other people do not have this issue, so I need to do some investigating on this.
- I don't have cellular data, nor MMS service. My APN erases itself a little while after I put it in. Edit: This was not a fixable issue; the phone does not have Google Fi's required bands.
I'm going to write another post about these last two issues, as well as another on some tips and tricks and the apps I use on my KY-42C. Thank you for reading!
Here's the English manual, should you want it.
Contact me: wiggle@mailbox.org
Edits:
2025-04-06 11:25 - Install all three microG apps instead of just two
2025-04-13 14:06 - Backup files from mtkclient
2025-05-22 00:03 - Compatible devices and operating system builds
2025-11-19 18:39 - Google Fi clarification + updated info about the mtkclient ISO + mtkclient Nixpkg + added menu names where the instructions used numpad buttons
2025-12-09 15:15 - mtkclient Nix derivative working + add email
2026-02-24 22:32 - removed compatible device list