The ubiquity of mobile devices makes them well suited for field-based learning experiences that require students to gather data as part of the process of developing scientific inquiry practices. The usefulness of these devices, however, is strongly influenced by the nature of the applications students use to collect data in the field. To increase student success and satisfaction with these experiences, mobile learning applications must be intuitive and functional for students, and support a systematic approach to the complex process of collecting data during a scientific inquiry. This article examines how developers can take an iterative, user-centred design approach to developing mobile learning applications that scaffold the process of data collection by documenting the evolution of an iPad application called Habitat Tracker. This application was created as part of an integrated curriculum that includes online and mobile computing technologies and was designed to help students learn about the nature of science and scientific inquiry on field trips to a natural science museum. The results of this research include principles that developers can use to guide the design of future applications used to support scientific inquiry during field-based learning experiences.