1. Structured Data Markup - Free
  2. One Step Checkout - Premium 
  3. Enhanced Admin Grid - Free
  4. Anything by Aheadworks - Premium
  5. Wordpress Integration - Free
  6. Amazon & Ebay Integration - Free
  7. Crafty Clicks Postcode Lookup - Free / Subscription
  8. Custom Shipping Price - Free
  9. Mailchimp / Mandrill - Free
  10. Coupons over URL - Premium
  11. All shipping plugins by Webshopapps - Premium & Free
  12. Social Media Reviews by Yotpo - Free
  13. Sage Pay Integration - Free
  14. HTML Sitemap - Free
  15. CMS Version Control & Page Revisions - Premium