Out-patient medication administration was identified as the most error-prone procedure in modern healthcare. Most medication administration errors were made when patients acquired prescribed and over-the-counter medicines from several drug stores and use them at home without proper guidance. In this paper, we introduce Wedjat, a smart phone application that helps patients to avoid these mistakes. Wedjat can remind its users to take the correct medicines on time and keep an in-take record for later review by healthcare professionals. Wedjat has two distinguished features: (1) it can alert the patients about potential drug-drug/drug-food interactions and plan an in-take schedule that avoids these adverse interactions; (2) it can revise an in-take schedule automatically when a dose was missed. In both cases, the software always produces the simplest schedule with least number of in-takes. Wedjat works with the calendar application available on most smart phones to issue medicine and meal reminders. It also shows pictures of the medicine and provides succinct in-take instructions. As a telemonitoring device, Wedjat can maintain medicine in-take records on board, synchronize them with a database on a host machine or upload them onto an electronic medical records (EMR) system. A prototype of Wedjat has been implemented on Window Mobile platform. This paper introduces the design concepts of Wedjat with emphasis on its medication scheduling and grouping algorithms.