rank tracker recommendation

Hi,

what are you people using to track the rankings of your sites? I am looking for a rank tracker that automatically detects the keywords and URLs I'm ranking for, without me having to input anything. Well, input only the URL of the home page only, cause I assume I must input something in order for the tool to do its magic

Also, I realize that such a tool might not be free (well, I wouldn't offer it for free was I to own one, so....), but I think $10 / month is a price I can afford for this, or maybe a one-time $20 fee? I don't know... just recommend me some good tools / services and I'll take a look at the price and features on my own.

For now I only have 1 small (5-10 URLs) site to track, and probably a dozen keywords or so. So, I don't need something incredibly powerful to start, I just need it to automatically detect the keywords and URLs I'm ranking for, cause - besides the keywords I targeted the inner pages to - I don't really know which search terms google feels like ranking me for. That's why I want the software to read google's mind and just offer me the results

Thanks in advance for any good suggestion