default-user

Would https://quarto.org/ fit the bill?

https://www.navidrome.org/

Granted it requires a server, but is easy to use on any client as a web app.

Works on Firefox nightly (android)

If you are not averse to the R language, https://r4ds.hadley.nz/data-tidy is a good resource for skills and ideas that generalize beyond "tidyverse" and R.

Thank you so much for the responses!

I've never posted here before but this demands a sincere "thank you".

I just colorised some family photos from the 1930s to the 80s and the results are heartwarming.

Thank you for making this and making it free and, most importantly, easy to use.