ECAS (https://services3.cic.gc.ca/ecas/security.do) only works for Paper Citizenship Application. The statuses are few(Application received, In Progress, Decision Made, Completed).
New Tracker(https://tracker-suivi.apps.cic.gc.ca/) has detail info about each stage. Works for both paper and online application.
Makes sense to follow New Tracker.
I am not sure about Application Portal.
Awesome, thanks! So I'll just pay attention to the tracker once I'm able to register in a few days. (Oh fyi the application portal I meant is the the page/portal/site we use to fill and submit an online application, so I was curious if it has any relevance after submission but your answer has cleared that up