Android is becoming a platform for mobile health-care devices and apps. However, there are many challenges in developing soft real-time, health-care apps for non-dedicated mobile devices such as smartphones and tablets. In this paper we share our experiences in developing the HifoCap app, a mobile app for receiving electroencephalogram (EEG) wave samples from a wearable device, visualizing the received EEG samples, and transmitting them to a cloud storage server. The app is network and data-intensive. We describe the challenges we faced while developing the HifoCap app---e.g., ensuring the soft real-time requirement in the presence of uncertainty on the Android platform---along with our solutions to them. We measure both the time and space efficiency of our app and evaluate the effectiveness of our solutions quantitatively. We believe our solutions to be applicable to other soft real-time apps targeted for non-dedicated Android devices.