Edit your list

Runs in this page. Your inputs are not uploaded or saved.

Your result

□ Front door
□ Windows
□ Stove
□ Keys

A worked example

Home departure with Front door, Windows, Stove, and Keys produces four separate boxes. Repeated identical lines appear once.

Keep the list readable

Use a specific name for each door or appliance. The tool supports up to 50 distinct items of 150 characters each. Browser inputs are not stored by this site.

Keep the next check on your iPhone

Create the items manually in Is It Locked?. This browser draft does not transfer into the app. Check the items yourself, then record them.

Get the app free

iOS 27 or later. One place and one list are free.

The app records what you checked. It does not lock doors, switch off appliances, or verify their physical state.

Sources and review notes

Calculation conventions and boundary cases are documented above. The tool runs locally and is tested against arithmetic and calendar examples.