I have never heard of this program so it would probably be best to wait for someone that actually knows for sure or has used it. I did a google search and didn't see any spyware mentioned by Download.com, ZDNet, or DSLreports but it appears to have been made originally for Mac's. There haven't been that many downloads at either download.com or zdnet for the Mac, even though it appears to have been out since 2003 for that particular system. I also clicked on the link for the author that you provided and is you click on the "Windows" portion, it looks like that is a Beta. Here are the google results. I read 6 or 7 or them.
CleverKeys is free software that provides instant access to definitions at Dictionary.com, synonyms at Thesaurus.com, and more ? from almost all Windows or Mac OS programs, including word processors, Web browsers and most e-mail programs. With CleverKeys, the answers are just a click away.