Related Clues:
- Bonus item
- Item that doesn't come standard
- Extra something
- Something costing extra
- Build a third bedroom, say
- Oreos at an ice cream parlor, say
- Yogurt shop choice
- Put ball back into play
- Provide something extra
- Extra-cost purchase
- Player using this must be off pitch
- Augment with
- Software module that enhances an existing application
- Charge hardware?
- Optional ingredient