This works with hackable Switches running the custom firmware Atmosphere.
To install, download releases from the following pages:
You should have the following files in the following locations after downloading and installing to your SD card:
SD:/atmosphere/contents/01006A800016E000/exefs/subsdk9 SD:/atmosphere/contents/01006A800016E000/exefs/main.npdm
SD:/atmosphere/contents/01006A800016E000/romfs/skyline/plugins/libswitch_keyboard_controller.nro
SD:/atmosphere/contents/01006A800016E000/romfs/skyline/plugins/libnro_hook.nro