Everything on one screen: how often this usually needs to happen, the free way to set it on the iPhone you already own, and what changes if a phone call does it instead.
One-off — a single date and time. The free built-in option comes first below, because for plenty of people it is genuinely the whole answer.
One-off reminders carry the most risk per alert: there is no second chance next week and no habit to catch you if the single notification lands at a bad moment.
Why this one slips: The doubt starts twenty minutes after you have left the house, and by then a reminder is no help — the useful prompt is the one before you walk out.
iOS deliberately exempts alarms from the silent switch and from Do Not Disturb, so a Clock alarm makes noise even on a muted phone. It costs nothing. If it works for you, you do not need us — the catch is that an alarm is one tap to stop, and taps are cheap.
A silent banner still loses here: you are already at the door with your hands full when it appears, so it gets cleared rather than acted on.
With ReminderCall your phone rings like a normal incoming call — a real call over the phone network, not a banner and not an in-app alarm. You answer, and a voice reads the reminder out loud in the words you wrote. Answering is an action, which is harder to do absent-mindedly than clearing a notification.
To be precise about it: a call follows your ring settings rather than your notification settings. On hard mute it vibrates and takes over your screen instead of ringing out loud, unless you save the number as a contact with Emergency Bypass switched on yourself.
The doubt starts twenty minutes after you have left the house, and by then a reminder is no help — the useful prompt is the one before you walk out.
Weekly rhythms and one-off risks around the house, from bin night to the oven you walked away from. The failure is almost never that you did not know — it is that the prompt arrived at a moment when acknowledging it was easier than acting on it. One-off reminders carry the most risk per alert: there is no second chance next week and no habit to catch you if the single notification lands at a bad moment.
Read next: a reminder app for people who forget everything · reminders when your phone is on silent · weekly and monthly repeats
iOS deliberately exempts alarms from the silent switch and from Do Not Disturb, so a Clock alarm makes noise even on a muted phone. It costs nothing. If it works for you, you do not need us — the catch is that an alarm is one tap to stop, and taps are cheap.
The other free move, and often the more effective one: anchor it to something you already do without thinking — after the kettle goes on, before you lock the front door, as you sit down at your desk. A reminder attached to an existing habit needs far less from your phone. Try both for a fortnight before you pay anybody for this.