SEMRUSH

Semrush is not a typical keyword research tool; it offers so much more than just researching keywords.
Unlike other tools where you need to add seed keywords to start your research, here you just need to add your URL (or your competitor’s URL) and it will show you all of the keywords that are ranking for that site.
This makes it easier for you to find short-tail and long-tail keywords that you can target and beat out your competition.
You can get in-depth details on:

• Traffic stats
• Search engine reports
• CPC

& many other details that you need to properly manage an SEO campaign.
This is a highly recommended product.
However, this is a paid service & comes with a 2-week trial.