Online writer: black feller (7)
I believe the answer is:
blogger
'online writer' is the definition.
'blogger' can be an answer for 'writer' (I have seen 'Modern writer' mean 'blogger' so perhaps 'writer' could also mean 'blogger'). I am not certain of the 'online' bit.
'black feller' is the wordplay.
I cannot really understand how this works, but
'black' could be 'b' (as in pencil classifications) and 'b' is found in the answer.
The remaining letters 'logger' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for blogger that I've seen before include "like Guido Fawkes?" , "Person posting personal thoughts on the Internet" , "One writes a journal on the internet" , "Contemporary diarist" , "Modern writer" .)