The best app to remember if you locked the door

You're three blocks away, or already at your desk, and the question lands: did I lock the door? You almost certainly did — your brain just didn't record it. Apps solve this in three very different ways, and picking the wrong kind is how you end up with one more icon you never open. Here's the honest comparison.

Smart locks: the expensive answer

Hardware first. A smart lock (Schlage, Yale, August and friends) replaces or sits over your deadbolt and reports its real state to an app — some can even lock themselves behind you. If the doubt you get is only about the front door, this is the most complete answer money can buy. And that's the catch: money. You're looking at $150–300 plus installation, it usually isn't an option in a rental, and it answers exactly one question. The stove, the straighteners, the gas, the back window — the other things you spiral about — stay unanswered.

One-tap log apps: the sticky note

The second family is tiny single-purpose apps — "Did I Lock?", "Did I Lock Up?", "Door Reminder" and a dozen siblings. The idea is disarmingly simple: lock the door, tap the button, and the app stores a timestamp you can look up later. It genuinely works when you use it, and most are free.

The weakness is the same thing that created your problem: remembering. The app only helps if you remember to tap it at the door, and nothing reminds you to. Skip the tap once — precisely on a rushed morning — and the empty log reads like an alarm bell for something you probably did do. One-item tools also quietly train you to check one item, while the doubt happily migrates to the stove.

Routine checklists: built for the whole exit

The third family treats the lock as what it is: the last item of a short leaving routine. Routina is built this way, specifically for ADHD brains. You list the four or five things you actually spiral about, and the app nudges you at the times you leave — so the capture happens without prospective memory doing any work. Each item is one tap with a loud haptic-and-sound confirmation, which is exactly the kind of deliberate, multi-sensory action that does get recorded. Every check lands in a timestamped log.

Then there's the moment the apps above don't handle: you already left and the spiral has started. Routina's panic mode pulls up your last log in one tap — "Front door · locked · 8:42am" — and the loop dies on the spot. If a receipt isn't enough for your 11pm brain, voice and photo proof anchor the memory harder.

Which one should you get?

• You own your home, the budget is fine, and the door is your only doubt — get a smart lock. A sensor beats any log.
• You doubt exactly one thing, rarely, and you reliably remember apps exist — a free one-tap log app is plenty.
• You have ADHD, or the doubt rotates between door, stove, and straighteners — you need a nudge, a routine, and a log. That's Routina, and the first routine is free.

Whichever you pick, the goal is the same: one check that counts, and never turning the car around again.