With the mobile app some nice improvements are there to save password and support fingerprint and facial recognition.
However when we use federated azure login, it brings us to a Microsoft login page. The problem is the page you are spawning is a private session and will not support the checkbox to keep us logged in.
This means every time we use the app we have to click federated, type email address (login name), then type password, then be prompted to remember password (which doesn't work). It eliminates the convenience of using an app.