There are options to choose from:
1. SEO Manager -$20 / month
2. SEO Master - $12.99 / month
3. SEO All-in-one $8.99/month
All of them got Free-plan available, so try it out.
You could compare them yourself on the Shopify app, these three are the most cost-effective.
All the feature you will need for doing SEO shopify.