iMAT is a system of automatic medication dispenser and software tools. It is for people who take medications on long term basis at home to stay well and independent. The system helps its users to improve rigor in compliance by preventing misunderstanding of medication directions and making medication schedules more tolerant to tardiness and negligence. Medication schedule manager in iMAT can be deployed either on standalone automatic, intelligent medication dispensers, or on computers and smart phones accompanied with traditional pillboxes. In this paper, we present the design and implementation of PROMUS and the results of a user experience study. PROMUS is a medication scheduler manager and reminder for modern smart phone devices. Similar to the scheduler for the iMAT dispenser, PROMUS scheduler takes into account both user preferences and medication directions in generation of flexible medication schedules and compliance enforcement. In particular, we focus on the interactions between the user and medication schedule manager to avoid medication errors. PROMUS schedules medication events to be more flexible and friendly by grouping the medication doses to reduce the number of times medications are to be taken and allow the user longer response time. PROMUS also provides intuitive, visually appealing user interface, clear organization, and familiar terminology that can be acted upon in conformity with the original behavior of medication record keeping.