The Chronostone Personal Timer. ‘An elegant personal timer for once a day reminding’. It’s designed for pill takers and the like, but I’m sure that there are lots of other uses that it could be put to. $29.99.

‘Completely silent, private, and discreet. Only you will know when it reminds you, because it uses a vibration instead of a sound…Simply turn it on at the time of day when you want to be reminded. It will automatically keep reminding you at that same time every day until you turn it off, or until you re-set it for a new time…