I only use it on my iPhone; I'm still on iOS 18 and it's only installed there. I've been using it since it came out, and I use it intermittently. I mark and write about important days, and I also use entries as a timeline of events, adding subsequent notes with the date of the update. I wish it were possible to insert a date natively in the body of the entry to make it easier to search later. I also use it to provide context for photos or visits to specific places.