Are users redirected to your App from a landing/Home page ?
If not - it may be worthwhile to introduce this layer - for future apps , and to externalize security.

The landing page can take on authentication responsibility, and pass a token with the redirect.
It also gives you the opportunity to implement authentication later, after the app is ready.

Another advantage of a landing page is that it could display app status, such as during an outage, or maintenance.