appear vs check in

appear

verb
  • To bring into view. 

  • To come before the public. 

  • To become visible to the apprehension of the mind; to be known as a subject of observation or comprehension, or as a thing proved; to be obvious or manifest. 

  • To come or be in sight; to be in view; to become visible. 

  • To stand in presence of some authority, tribunal, or superior person, to answer a charge, plead a cause, etc.; to present oneself as a party or advocate before a court, or as a person to be tried. 

  • To seem; to have a certain semblance; to look. 

check in

verb
  • To visit in order to see how someone is doing. 

  • To verify a person's information and record their arrival, such as at a hotel, airport, etc. 

  • To integrate new revisions into the public or master version of a file in a version control system. 

  • To announce or record one's own arrival at a hotel, airport etc. 

  • To contact another person in order to keep the other person informed of one's situation. 

  • To return (a book to a library, source code to a repository, etc.). 

  • To enter solitary confinement at one's own request for protection from other prisoners. 

  • To send somebody to solitary confinement; to make somebody be admitted to solitary confinement. 

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