I am using Google analytics & Google webmaster Tool for doing SEO because I can check website' s traffic or report on Google analytics tool and website's health or errors reports in webmaster tool.
Search engine tools help to optimize your website better and help rank keywords higher in search engines. They are used to build your daily traffic and popularity of your business online.
Google Webmaster Tool
Google Adwords
Google Analytics
SEOsitecheckup (for on page issues)
Smallseotools (for content spinning and writing)
Majestic SEO
Google Analytics is my favorite SEO tool which is used to track the visitors to my site. Next I use Google webmaster tool to find the backlinks. Other than these I use opensiteexplorer.org, rank checker etc.
There are lots of tools in SEO which helps to analyze the complete functioning of a website and to track the analytics of a website easily. Some of them which are very useful are listed below:
1. Google Webmaster
2. Google analytics
3. Moz
4. SEOptimer
5. aherf
6. Smallseotools
7. Google Adwords
8. SEMrush
9. Copyscape
10. Serpbook