I enjoy following Massimo Pigliucci’s How to Be a Stoic blog—he’s a fine writer on the subject (I have also learned a lot from hearing him talk about the philosophy of science)—and recently discovered he does a short but frequent podcast called Stoic Meditations.
Each episode is under three minutes long. Pigliucci gives a reading of a line or two from one of the ancient Stoics, then discusses it briefly. It’s short and to the point, but leaves you with much to think about for the day.