Don’t know if anyone else on here rows, but those of us who do are addicts!
Concept2 is the gold standard ERG, and has an excellent API through its PM5 and ErgData platform.
I created the wrapper below to display This Week, L4W, and Season To Date rowing data for this season and last, although it can be highly customized (by modifying the underlying javascript).
Repository is located here: https://github.com/shehant/mmm-concept2
Will caveat, the coding is somewhat hacky and there’s not a lot of documentation (I’m not a techie…)