Abstract: A device mountable on a medicine container for indicating whether a pill has been taken, which includes a set of keys and a plurality of open grooves with rounded ends. Atop the elongated base of each key is a small protrusion, which, like each groove, is generally oval in shape. In assembled relation, each protrusion is slip-fitted into one of the grooves. Slideable along the length of the groove, the protrusion, while it abuts one or the other groove end, is held temporarily in one of two distinctive positions. In view through an elongated portion of the groove not occupied by the protrusion is only one of two distal ends of the elongated base—provided the protrusion abuts a groove end—and the distal end's distinctive indicator marking. By sliding one protrusion to the opposing groove end after each use, a patient can easily record his pill consumption.