A note that lives on the thing it's about
Each Remember Sticker has a QR code. Scan it with your phone's camera and a note opens. Type anything: the filter size for the furnace, the paint colour for the hallway, the last time the mower blade was sharpened. It saves as you go.
Scan the same sticker next month and the same note opens. There's no app to install and no account to make.
Turn on the button and each press records the date and time, so you can see at a glance when you last fertilized the lawn or changed the water filter.
Anyone who scans a sticker can read its note, so don't write anything private on one. Add your email, and you can see all your stickers from a computer and lock a note so that only you can change it.