What are the exclusive features that are part of subscriptions only?

These features are not available on Pay-As-You-Go credits:

• Boosted Keyword Finder (see screenshot below).
• Keyword rank tracker (100 on the standard plan | 500 on the premium).
• Domain Explorer, contains 150K weak websites for your competition analysis.
• Competitor keyword extraction.
• Sitemap Extraction Tool
• Unlimited access to free report downloads 
• A 10% discount on pay-as-you-go packages 

Boosted KWFinder example :