Here's the compiled NRO which has to go to the Switch's SD card (sd:/switch/n1dus/n1dus.nro).
If a keys file is present, XCIs can be installed as well.
It will look for for keys.dat, keys.txt or prod.keys in '/', '/switch', or '/switch/n1dus' I recommend dumping all needed keys with Lockpick:
https://github.com/shchmue/Lockpick/releases
Since the original author abandoned the project this can be considered the final release.
