The application is built using python and kivy. It is packaged for android using the buildozer toolset: https://github.com/kivy/buildozer
A bit of the front end comes form some of the plyer examples, check them out here:
Accelerometer data is smoothed using median smoothing with a sliding window of 50 samples (15 sample overlap) From there, peak detection determines steps. The red bar on the graph here indicates each time someone is stepping.
