app vs software

app

noun
  • An application (program), especially a small one designed for a mobile device. 

  • application (to a college etc.) 

  • appetizer 

  • an appearance in a game (e.g., a player with 10 apps in a season played 10 times) 

  • application (use, purpose; not a computer program) 

software

noun
  • Hyponyms: application software, data-oriented software, kitchen table software, on-premises software, malware, schlockware, shareware, shovelware, spyware, system software 

  • Encoded computer instructions, usually modifiable (unless stored in some form of unalterable memory such as ROM). 

  • The human beings involved in warfare, as opposed to hardware such as weapons and vehicles. 

How often have the words app and software occurred in a corpus of books? (source: Google Ngram Viewer )