Stupid Questions

[Dreamcatcher]

OK, keep in mind that I'm new here and maybe not that bright. I have seen posts with these nice icons for spades, hearts, diamonds, and clubs (no green clovers, but, whatever). I have also seen some references to a "converter". I must admit I did a search on it and got lazy when I couldn't find a link to it. Is there a link to this program?
Next dumb question, I have seen the abbreviation CO a lot. I have used my incredible powers of deduction to assume this is the late position player who is not on the button. I'm curious what the abbreviation stands for and if my assumption is correct?