code: function enable(app, route, repoDir){
    expressApp = app;
    routePfx = route;
    if(repoDir){
      reader.setRepoDir(repoDir);
    }
    app.post(route, androidUpdate.updater);
  
    app.get(route, function (req, res){
      res.send(reader.available());
    });
  }
docs: Enable auto apk updater for provided Express application and route.
  @param {@Object} app parent Express application
  @param {@String} route route prefix for current updater
  @param {@String} repoDir path for apk directory