add-on

Noun (3)

1. a software module that extends or enhances the capabilities of an existing applicationSynonyms: plug-inType of software, software program
2. a component that is added to something to improve it“the addition of a bathroom was a major improvement”“the addition of cinnamon improved the flavor”Synonyms: additionimproverType of component, constituentKinds additive, attachment, annex, afterthought, elongation
3. a supplementary component that improves capabilitySynonyms: accessoryappurtenancesupplementType of component, constituentKinds fitting, fixings, auto accessory, computer accessory