People living with chronic health conditions have two common challenges: implementing positive health behavior habits, and monitoring & reporting their health status regularly. We examined how the use of a mobile app can help patients face these challenges in the context of a scenario in which a patient needs to weigh themselves daily and report the data to their care team. We implemented a habit formation technique to help people establish the daily weighing habit and tested the use of a WiFi-connected "smart" scale to help people with data reporting. We found that the smart weight scale did improve compliance compared to a manual scale, but that the habit manipulation ("implementation intention" plus coaching through text messaging) did not have an effect. Emergent factors, identified through coding of interviews, raised additional hypotheses about mechanisms involved in determining compliance with a daily weighing habit.