Hi Jennifer,
I'm sorry, but Little Reader (and Little Math) is not Mac-compatible, and this is why you couldn't open or run the trial software that you downloaded. While we do plan to do so, unfortunately the Mac versions of our software won't be available anytime soon. Kindly have a look at this article for further information:
http://support.brillkids.com/entries/20349238-will-brillkids-software-work-for-mac-os-usersIn the meantime, we do know that there are a few Mac users who were able to run Little Reader by first installing Windows on their Macs via Boot Camp, Parallels, or other similar software. Although we are unable to provide full support for Mac users (since our software have not been tested in a real Mac environment), we will still do our best to help in case there are problems encountered while using our software this way.
Also, in case you own an iPad, iPhone, or iPod Touch, you may want to try out our new Little Reader Touch app, which is currently available for free at the App Store:
http://www.littlereadertouch.com/