It would be a nice feature to create a recurring note. Recurring workouts are cool, but say I wanted to remember a client's birthday or the day they joined for customer service reasons - (yes I could do this with google calendar, but I'd rather keep all my client data in one place!). Recurring notes that could repeat in a client's calendar that are visible only to me would be helpful.
Even making an "event" invisible to the client, and making it recurring would be fine. Doesn't have to be a note.