I'm Building A Rank-Checking App, Need 'Features' Input

At least half of what I do online involves organic, or search engine traffic. As such, the positions my sites hold for their various keywords are very important to me.

Currently, I use Traffic Travis to monitor my sites. I can input each site, along with the keywords I'm targeting or tracking. The program stores these in a database, and when I click 'update' it looks for each site's position, for each keyword/phrase I've specified.

The program does many other things, but it's buggy, and the only thing I use it for is tracking rankings.

Since 'position monitoring' is so central to my business, I've decided to build an app that does this for me.

I'd be very interested in any input, since I'll probably end up making it available once it's built.

My personal criteria are that it does 'basic' rank-checking, meaning a database that stores URL's plus the keywords I want to track for each, checks Google, Yahoo, and MSN down to position 100, and gives me a current position, 'last' position (from whenever I last checked), and 'best' position (the highest the site has ranked since I input it).

I want to avoid 'bloatware' - one of the problems with Traffic Travis. I don't want to create an "all in one" tool, just a basic but thorough rank-checking tool.

I'm hoping to end up with something I would be happy to pay $10 for myself and feel I got a reasonably good deal, on a tool that does what I want it to.

While avoiding "feature creep", is there anything else in terms of rank-checking that should or could be included?

Thanks in advance,

Mark