app.js

app = angular.module("myApp", ["service.create"])

controller.js

angular.module("myApp").controller("testCtrl", function($scope, create) {
  return console.log(create);
});

services.breadcrumbs.js

angular.module("service.create", []).factory('create', function() {
  var self;
  self = {
    "status": "hello"
  };
  return self;
});

app = angular.module("myApp", ["service.create"])
defines a module here, the "myApp" module dependencies is defined here and cannot be changed. It's dependencies is ["service.create"].

Later, you call angular.module("myApp") to just get the "instance" of that module. It's the same one with previous 'app'. You cannot add dependencies here since it'll create another new module and override "myApp"

I will use
angular.module("myApp", ["myApp.controllers", "myApp.services"]);

angular.module("myApp.controllers", ["ui.router"]);

angular.module("myApp.services", ["ui.bootstrap"]);