Ahrefs is a great SEO tool like SEMrush. It helps you find good keywords for your website and keeps track of your competitor's website. It helps you to know why your competitors are ranking so well and what you need to do to surpass them.

Tools available with Ahrefs:

• Competitive Analysis
• Keyword Research
• Backlink Research
• Content Research
• Rank Tracking
• Web Monitoring

There is no free version available. Its Monthly plan Lite starts at $99.95 but you can use its 7-day trial version.

How to Use Ahrefs for SEO and Competitor Research

Its a very easy process, if done in steps.

1. First select a keyword like "Food delivery app"

2. Do search this keyword on Google search

3. Pick the top 3 links 

4. Go to the Ahrefs > Content Gap tool. Add links to the three inputs, we copied before

5. Then click on show results

6. In settings bar change intersection to 2, to get more ranking keywords

7. Now find keywords ranking in different countries and note down

8. Modify the content and add those keywords which your competitors are ranking for

You can also check backlinks to find sites linking to the competitor this way