Band Heart Rate Graph

This app plots your heart rate in real time as soon as there is data available. The default Microsoft app only offers low resolution data while this one will update your heart rate every second so you can monitor it during a certain exercise (or any kind of stressful event). This app grabs the raw data with no filtering other than removing BPM values above 220 (which are likely to be inaccurate). You can also save a log of your heart rate to a CSV file so you can review it later on a computer with a program of your choice. The app now runs in the background while your phone is locked so you can leave it running for an entire workout.This app currently requires a Microsoft Band 2 and the Microsoft Health app to be installed.
This app also requires access to external storage so that it can store CSV files in your phone. The CSV files are located in the Documents/HR Graphs folder and are automatically time-stamped.
Please suggest features, I am happy to try and add them!