Full disclosure up front: we make Reembr, and it's in this list. But this is written to be genuinely useful for deciding between these, not just a pitch, so we've tried to describe each one the way we'd want it described if we were choosing.
Reembr
Geofence-based leaving and arrival checklists, free, iOS and Android. You save a place, like home or work, attach a short checklist to it, keys, wallet, charger, whatever you tend to forget, and Reembr notices the moment you actually cross the edge of that place and shows you the list right then. Detection runs entirely on your phone; nothing about your location or your comings and goings is uploaded anywhere.
Best for: people who want the reminder to happen automatically, with no manual check-in, and who care specifically about on-device privacy rather than just being told an app is "private."
Where'd I Put It
An ADHD-positioned reminder app that combines geofencing with Wi-Fi network detection (so it can also nudge you based on which network you're connected to, not just GPS), plus voice-memo logging so you can talk a reminder into existence instead of typing it. It shares Reembr's on-device privacy angle.
Best for: people who want voice-first logging and like the idea of Wi-Fi-based detection as a backup to GPS.
Before You Go: Checklists
A location-based checklist app with a wider net of built-in use cases than just keys and wallet: daily medications, turning off appliances, feeding pets, and grabbing work equipment. It has Apple Watch integration and syncs across devices.
Best for: Apple-ecosystem households who want checklist templates for household routines beyond the classic keys-wallet-charger set, and who'd use the Watch integration.
Native options: Apple Reminders and Google Keep
Both let you set a single reminder tied to leaving or arriving at a location, for free, with nothing to install. Apple Reminders does this through Siri or the Reminders app directly; Google Keep offers a similar location trigger on a note.
Best for: a single one-off reminder, like "remind me to grab the dry cleaning when I leave work today." Neither is built for a recurring, multi-item checklist that runs every time you leave a place, which is the gap the dedicated apps above are built to fill.
Which one should you use?
If you want a full, recurring checklist that shows up automatically on both leaving and arriving, with your location data staying on your phone, that's exactly what Reembr is built for. If voice-memo logging or Wi-Fi-based detection matters more to you, Where'd I Put It is worth a look. If you're deep in the Apple ecosystem and want Watch support plus templates for household chores beyond the doorway, Before You Go covers that ground well. And if you just need one single one-off reminder and don't want to install anything new, the native option on your phone already does that.