Keyword Search Tool

Hello friends,
Yesterday I had a discussion with one of my SEO friend about the SEO tools. I told him that I check the keyword position manually and he told that he is using the tool seoserp[dot]com. And according to him it gives the relevant result. So Even I thought of checking that tool but found that all the results were different from the manual search result and I found the one of my keyword which was on the position 5th while that tool shows its position 12 in Google.
Please share your thoughts on this tool if anyone is using it or know about it..

Thanks