Cookie Cards
A private family website: five of us collect Pokémon and football trading cards and use this to keep track of what is coming out, what is in stock, what we paid and what we pulled. It sends us reminders and keeps our records. It does not sell anything, it does not buy anything, and it is not open to the public - every page needs the family password.
It uses a Google account we own to send ourselves email, keep a calendar of release dates, store nightly backups in one Google Drive folder, and read our own order confirmations from one Gmail label.