A good setup looks like this. Every deadline entered the day you decide to apply to that school, not the week it is due. Two alerts per deadline: one a week out, one the day before. An application deadline alert app with push notification does the pinging, but you have to give it the dates early enough for the pings to matter. An alert set the night before is a condolence card, not a reminder.
The failure mode is notification blindness. If your phone buzzes forty times a day, one more buzz changes nothing. Fix it by making application alerts sacred. A distinct sound. A separate calendar. A rule that you never dismiss one without acting. Snooze is fine. Dismiss-and-forget is how deadlines die.
Do you even need a dedicated app? A free application deadline tracker app earns its place if you are juggling eight-plus programs, because it shows the next deadline across your whole list at a glance. Under five programs, Google Calendar with aggressive alerts does the same job for free. Match the tool to the size of the problem. I have seen people over-engineer a three-school season and under-tool a twelve-school one.
One more thing the apps cannot do: verify the dates. Deadlines move, programs add rounds, and department pages contradict graduate school pages. Check each date against the source twice. Once when you build the list, once a month before it is due.
So yes, they work. One condition. The app reminds. You act. Keep that contract and an application deadline tracker becomes the cheapest insurance in your whole application.
Real dates to feed it: university application deadlines 2027 by program are tracked at applicationreview.fyi. Once everything is submitted on time, get your application audited before the portals close.