The FunKey S runs FunKey-OS, a purpose-made open source Linux distribution. Launchable from one of the device's two application launchers, the device's seven default emulators enable the emulation of twelve consoles out of the box, with Game Boy Advance and improved PlayStation emulation requiring the addition of BIOS files by the user. While the list of consoles emulated out of the box is expected to grow with future firmware updates, third-party emulators can also be used to give the device additional emulation capabilities. While the device includes 61 homebrew games to help demonstrate its functionality, users may also add their own games and box art to the device's emulated system folders to expand their FunKey S game catalogue. Should the need arise, users can edit or delete any file on the device via Commander, the included file management application, without the need to connect the FunKey S to a computer. As FunKey-OS is open source, the files used to build it are publicly available on the FunKey Team's GitHub page.