Gyazo
Used by 4 peoplegyazo.com ↗

“I also like Gyazo, a simple tool to share screenshots quickly.”
Sadayuki Furuhashi Interview, Hacker (MessagePack, Fluentd) · via Uses This 
“Gyazo is my favourite no-nonsense screencapture app.”
Divya Manian Interview, Web developer (Opera, W3C, HTML5 Boilerplate) · via Uses This