uxforthemasses.com have created a great list of 25 free ux tools for doing things like prototyping, annotating, screen grabbing, site mapping, usability testing, accessibility and analytics (thanks guys!). Some of the items aren’t really free (they just have a free trial), i’ve included them anyway as they’re still really useful and i’ve added a few of my own.
Flairbuilder (15 day free trial)
Powerpoint (Open office version is free)
Pen and paper! The simplest and arguably the best. Frees your mind to be creative, can be used anywhere and is ultra quick.
Screen grab tools
Cmd shift 4 – If you’re using a mac you can use cmd shift 4 to capture a portion of the screen or cmd shift 3 to capture the whole screen.
Print screen – On Windows PCs you can just use the print screen function and paste it into Word, or Powerpoint if you want to do a click through prototype.
Usability testing tools
Remote usability testing tools
Silverback (free for 30 days)
Usability reviewing tools