Yes I would be interested in PPM meters in the recording screen, they are actually in the Rockbox
recording monitor screen, they could do with a bit of colour graduation as the signal gets hotter towards peaking, but they do function very well!
But once stuff is mangled by Optimod (radio compression) and down to 96k bandwidth, it makes one wonder sometimes why anyone bothers to record sweet anyway.

The compressor/ limiter used in Spotify is quite interesting though, seems to level classical music pop, death metal et al so you are not always reaching for the VOLUME knob.. some people are not keen on it though.
http://en.wikipedia.org/wiki/Loudness_war