Rated 2 out of 5 stars
WARNING: Don't install the screengrab (fix version) by Alexander, he's a shady Russian hacker. Who has domains registered in China.
Screengrab was good while it lasted, I'm giving it a 2 star rating because it's no longer supported by the original developer. It was great while it lasted, no screencapture addon came close to it. (I'd say it was a 5 star addon.) Fireshot is way too bloated and gimmicky to compare to it.
Edit: Okay, so maybe it's not malware. I still think Alexander is a shady Russian hacker.