unmoderated user testing

Which tools are you using for remote usability testing and unmoderated user testing?

Hello everyone,

We're shopping for an unmoderated user testing tool and I'd like to know which tool you would recommend.

There are several tools out there... I found Solidify app (for prototyping test) by ZURB. Anyone using it? If so, how do you rate it as usefull in terms of detecting early usability problems in the prototype or mockup? If it has helped you, how?

If you has used other tools, how'd you rate it (pros xs cons)? 

Thanks.

Patricia