My SEO needs are surprisingly modest. Although I have a lot of keywords I track, I have a need for a tool that would be particularly useful to beginner or mid-range SEOs. I mocked up this tool idea in an hour or so. If I coded it, would you use it? Would you pay for it?
This is a tool I need, built exactly with the features I want. It's not intended for massive SEO campaigns, and I'm sure there's a huge list of potential features you could come up with. If I were to build it, I'd keep it dead simple and create it just like this mockup. It wouldn't require an account, either, so you'd just visit it, set up your keywords, and be on your merry way.
I'm probably going to build this SEO tool whether the SEO community needs it or not. I'm just debating whether I should make it public or keep it for myself.