Update app.js

[Huskydog9988]

Please describe the changes you made:

Fixed issue with undefined app. It was below other vars that were using it.

Type of change: Select one or multiple if needed.

• [x] This PR include bug fixes.
• [ ] This PR include minor improvements. (no big new feature)
• [ ] This PR include major improvements. (like a new feature or module)
  • [x] IF ONE OF THE THREE ABOVE: The features or fixes made in this PR were tested.
• [ ] This PR include no changes to the code but to other repository files.