Set it up once. Never think about it again. That's the whole appeal of a mobile app for dividend payout alerts, and honestly, it's the best feature category in dividend apps.
Three alerts matter. Ex-dividend date warnings, two trading days ahead, so you never buy a day late and miss the payout. Pay date confirmations, so you know the cash landed without opening your brokerage. And dividend change alerts: increases, cuts, suspensions. The cut alert is the important one. A dividend cut is the market telling you something broke, and hearing it from a notification beats hearing it from your statement a month later. I learned that one the slow way.

Setup advice from someone who's been burned: keep the alert list tight. Alerts for every holding, yes. Alerts for your whole fifty-stock watchlist, no. Notification fatigue is real, and the day you start swiping away dividend alerts without reading them is the day the system stops working. Ten holdings, ten alerts, done. Discipline beats coverage.
The free question, as always. A dividend payout calendar app free tier usually includes basic alerts, and that's enough. Paying for alerts is paying for a push notification, which might be the silliest subscription in finance. Save the money. Buy half a share of something instead.
Pair the alerts with the calendar and you get the full picture: the dividend payout calendar shows the schedule, the alerts make sure you notice it. And for the research behind the alerts, which stocks even deserve a place in your portfolio, a dividend income calculator app on iOS or Android handles the income math while the dividend income planner at dividenddb.fyi handles the screening.
Simple system. Set and forget. Check in once a quarter.