An app build to collect motion data from the build-in sensors of Iphone, and it can visualize the data/change of data on graphs Sorry I only ended uploading everything more than a year late. But it ran smoothly summer 2019. It can be automatically built from Xcode and its compilers. However, one issue is I messed up with expiring developer license. You must have one to run it on the phone. It is used as a research tool instead of commercial product for Chengdu Subway.