In some embodiments, an adjunct device for tracks time and/or dosage of a medicine. The device may include a connector for mounting the device to a deposable pen injector. The device may be configured to allow use of the native controls and injectors of the injector. For example the device may include a view port for viewing a dose indicator of the injector. The device may include one or more vibration sensors. A processor may be configured to differentiate increasing a dose, decreasing a dose and/or discharging the medicine based on the output of the sensors. Optionally a display of the device may be positioned for simultaneous viewing with the dosage indicator of the injector. For example a user may verify the accuracy of the adjunct device before performing a discharge.
