Tools for screen capture : Web, Window and Mac

From time to time, I will need to screencap a website or jpg and then make annotation on it. Here are 2 tools I found useful to do that job :

1. for website, there is a chrome extention to take screen shot, add shape, arrow and text to it https://chrome.google.com/webstore/detail/alelhddbbhepgpmgidjdcjakblofbmce

2. for desktop screen cap, there is a similar tool that could be use on Window and Mac : http://jshot.info/

install them and you will find it handy when you need to comment on screen design or report bug.