List of third-party OPK applications

This article lists third-party OPK-format applications built for the FunKey S. Freely downloadable from this page, these applications allow users to add additional functionalities to their devices. Note, however, that as the device's Instant Action autosave feature is implemented on a program-by-program basis, users must remember to manually save their progress in any third-party program that hasn't implemented the Instant Action feature. Also note that while many devices use OPK as an application format, only OPK applications compiled specifically for the FunKey S are compatible with it. Once a FunKey S OPK application is downloaded, it can be installed by simply placing it in a folder at the root of the device's file system, with the Applications, Emulators, and Native games folders available by default for file management. Applications available for download on this page are organized as they would be accessed from the Gmenu2x launcher — into the following three groups:







Should you wish to build or modify OPK applications yourself, you may download a version of SquashFS configured for editing OPK applications on Windows here. After extracting the SquashFS folder from its ZIP archive, add the OPK file that you wish to edit to the folder and double-click the ''1. EXTRACT_OPK.bat'' file. This will create a folder called squashfs-root, containing files for the application's configuration settings, icon image, and binary data. Unless you have prior experience configuring OPK applications, however, it is recommended that you only modify the icon file, a 32-pixel square PNG format image file that represents the application in Gmenu2x. In doing so, ensure that the replacement icon file is also a 32-pixel square image, in PNG format, and named exactly as the original file was (icon.png is replaced with icon.png). Once you have finished modifying the application, return to the SquashFS folder and double-click the ''2. MAKE_OPK.bat file, which will apply your modifications to the submitted OPK'' file. After several windows pop up and disappear, your application will be modified and ready to be returned to your FunKey S. Note that if there are multiple applications that you wish to modify, you must do so one at a time. For additional instructions on how to use SquashFS to modify or build OPK applications, it is recommended that you join the FunKey Community Discord Server.

Applications
The following applications are any programs for the FunKey S that are neither emulators nor games. Alongside each application is listed a general description of it.

Emulators
The emulators listed in this section add to the capabilities of the FunKey S by enabling improved emulation of several supported systems and general emulation of several unsupported systems. As a means of helping users choose which emulators to use, especially for cases in which there are multiple options, the following table lists currently unsupported systems on the left with the best emulators currently available for them on the right:



Should a system not be listed above, it is either already officially emulated by the FunKey S or has unofficial emulation that lacks sufficient functionality for use by a general audience. To illustrate cases of the latter, each emulator is rated from low to high for both overall emulation accuracy and speed. In addition to the emulators listed on this page, should you wish to emulate the BBC Micro, CHIP-8, or ZX Spectrum, meta-emulation is an additional option for third-party emulation. Should one of the emulators listed on that page be incompatible with the default gpSP emulator, however, the SDL Retro mGBA core or the standalone VBA Next emulator would be needed to use the meta-emulator.

SDL Retro
Two options for using SDL Retro are available: All-In-One and One-By-One. As the first of these includes all default SDL Retro cores in the OPK file itself, all the user must do to install it onto their FunKey S is add it to a folder at the root of the device's file system just like any other application, emulator, or game. Should you prefer to only have the emulator cores you intend to use installed, and thus speed up the SDL Retro's core selection process, you may alternatively download the One-By-One option. While its download also includes an OPK file, the emulator cores themselves are included in a separate cores folder that must be placed in the /mnt/FunKey/.sdlretro file location of the FunKey S for SDL Retro to function. If one or more required BIOS files are listed alongside a core you wish to use, ensure that those files are named and located in the /mnt/FunKey/.sdlretro/system file location for optimal emulation results. In the case of blueMSX, download, extract, and place that emulator's Databases and Machines folders in the /mnt/FunKey/.sdlretro/system file location. In the case of Neko Project II Kai, the required PC-9800 files listed in the table below should be placed in the /mnt/FunKey/.sdlretro/system/np2kai file location. If you don't see the .sdlretro folder, your computer's Unix-based operating system is hiding hidden folders.

Standalone
If one or more required BIOS files are listed alongside an emulator, ensure that those files are named and located in the following file locations for optimal emulation results:


 * /mnt/FunKey/.3doh for 3DOh
 * /mnt/FunKey/.pcfxemu for PCFXEmu
 * /mnt/FunKey/.smsplus/bios for SMS Plus GX

If you choose to use the version of SMS Plus GX included in the SDL Retro OPK, follow the instructions listed in the section above instead. As PCSX ReARMed Ultimate and PicoDrive simply replace their default counterparts when initially loaded, their BIOS files (if not already present) go in the regular /mnt/PS1/bios and /mnt/Sega Genesis/bios file locations, respectively. Should you wish to instead add FinalBurn Alpha 2012, Gambatte, MAME 2000, or VICE to the SDL Retro OPK to lessen the number of icons present in the Emulator tab of Gmenu2x, you can alternatively download, extract, and place their SO format emulator core files in the /mnt/FunKey/.sdlretro/cores location of the FunKey S file system (if the cores folder is not already present, create it first). If you don't see the .sdlretro folder or the .3doh, .pcfxemu, or .smsplus folders disappear upon creation, your computer's Unix-based operating system is hiding hidden folders.

Games
The following applications are freeware games that have either been ported to or natively developed for the FunKey S. To facilitate list navigation and game selection, alongside each game is listed its genre. To play the OPK ports of commercial games, one or more additional files containing necessary copyrighted assets must be provided by the user from their own legally acquired copy of the game. The data files of such games should be grouped together in a folder located at that game's listed file location. Games requiring several of a specified file type to run have an asterisk placed after the applicable file type(s).

Make note of the following information for the following games:
 * While Doom, Doom II, and Final Doom only require a single WAD file each, add-on WAD files also can be used
 * While Quake only requires its PAK0.PAK file to launch, to access the full game, the PAK1.PAK file is also required
 * Due to the FunKey-OS V2.3.0 update, VVVVVV is currently non-functional

If you don't see the .local folder, or the .cannonball or .ecwolf folders disappear upon creation, your computer's Unix-based operating system is hiding hidden folders.