SEO Tools

Here, let’s keep a list of useful SEO tools. I’d like to start it off with some tools I use personaly.

• SEHabitat: It’s the software I use to manage and track growth of all my websites. It tracks my rankings and helps me manage link building and the financial aspects of running many sites.
• Term Explorer: I use this for keyword research.
• …that’s it for me. Any tool suggestions?