Use string interpolation

src/client/app/mobile/views/pages/user.vue

@@ -107,7 +107,7 @@ export default Vue.extend({
 				this.fetching = false;
 
 				Progress.done();
-				document.title = Vue.filter('userName')(this.user) + ' | ' + (this as any).os.instanceName;
+				document.title = `${Vue.filter('userName')(this.user)} | ${(this as any).os.instanceName}`;
 			});
 		}
 	}