Buggy like hell. Destroyed our launch by constantly misbehaving. Even though the option of "hide timer after it expires" was chosen (and not the "redirect to URL" option, it kept redirecting visitors off to a non existent page adding the word "false" (eg. our sales page was at example.com/sales/ and visitors were redirected to example/com/sales/false - which resulted in a 404 error.
And the HUGE bug in the plugin, is that our server is in PST timezone. So for someone who visited from a timezone much ahead (say, like GMT+8 - like London, UK), the plugin was redirecting to the fake page, but when we tried it, it would load fine because it hadn't expired for the visitor in the "right" time zone.
Bottomline: Doesn't matter if it's free, but even if they paid us, we wouldn't use it.