yes, its a noninteractive test script, loads the SoftCut engine and sets some parameters. there’s not much else to tell. it is not actually broken or half-written, just not very interesting. sorry it was included on the shipped image. feel free to add some controls and make an interesting delay to your tastes.
no, i have not made any kind of “fully featured” looping application at the moment. most of my work on norns has been on backend features, building the device tree, the event loop, the SC class system, the scripting / C glue, the reverb and compressor, the ugens and engines underlying mlr and earthsea, &c. i’ve barely used it for music.
most of my musical applications of computers are noninteractive anyway and very simple (delays and sinewaves, most musical decisions and materials being relegated to human beings) - and i tend to make many small programs with specific functions, not big programs with lots of “features.” so they might disappoint you in the end.
i’ve basically taken a week-long break from norns. meant to do some backend work but have been busy with Life Stuff, day job and mixing a record. will get back into it shortly but my issues list remains backend work supporting the creative needs of others. this is fine. but my goal is to enable you to make your own looper. 
i do enjoy the elementary CA harmonic sequencer thing, which also demonstrates pitch sampling and other system features we haven’t really talked about yet. i’ll integrate it with param system and re-add.
really!? oh dear ok. well, the takeaway is that it is easy to adapt the SoftCut engine used by MLR to other kinds of looping / sample cutting / echo interfaces. i would prefer to leave the UI design and implementation to others but i can make an interactive example or two to get the ball rolling.
at the moment though, i am putting my time into looking to make better use of the norns’ multiple cores to distirbute DSP processing, allowing us to revert some last-minute cuts to audio quality, improving MLR and other applications of varispeed tape-like audio buffer manipulation. (https://github.com/monome/norns/issues/407)