Firestorm is what I currently use, But since the most recent update it's for whatever reason been slow for whatever reason (Prior versions) were fine.
And yeah, admittedly I already deal with Generalized Anxiety Disorder, when I saw the little prompt pop up I went into a full panic, and deleted everything and blocked him, I'm frankly unsure if he realized what he was using was a 'no no' or was perfectly aware.
No idea what Cool VL is, I know.. Black Dragon (Which runs absolutely terribly for me) and Firestorm, and I remember some mobile viewer way back but that's about it. I'm aware there's probably a resource for this kind of stuff around, but Firestorm has always pretty much been decent enough.