What SEO Tools are useful to use?

Google PageSpeed Insights.
Moz Local Listing Score.
Keywordtool.io.
Google Analytics.

The best tools for website optimization are:

Google keyword planner
Google analytics tool
Google webmaster tool
Google Adwords
Ahrefs
Copyscape
Moz SEO tools

1. Google PageSpeed Insights
2. Moz Local Listing Score
3. Keywordtool.io
4. Google Analytics
5. Google Webmaster Tools + Bing Webmaster Tools
6. Open Site Explorer
7. Google Keyword Planner
8. Google Trends
9. QuickSprout Website Analyzer
10. Schema Creator
11. SimilarWeb
12. SERPs Rank Checker
13. XML Sitemaps
14. Browseo
15. SEO Site Checkup
16. Searchmetrics Website Analyzer
17. Find Broken Links
18. Copyscape
19.Moz toolbar
20.Robots.txt Generator
21.Structured Data Testing Tool