About this app

This app uses your device's built-in sensors to measure a person's breathing and heartbeat rates. It turns your Android device into a heart monitor, useful for workout and exercise fitness regimens.

It is the only app on the market that uses two different methods to measure the heartbeat rate. One method monitors chest movements. The other uses the rear camera and light to monitor blood flowing through a finger tip.

With the first method, your device collects sensor readings several times each second while the device is resting on the subject's chest. The app makes use of a technology in your device called 'sensor fusion,' which combines the readings of multiple sensors to isolate such variables as linear acceleration, rotation, and gravity. The app monitors the change in angle to determine the breathing and heartbeat rates. To use this app, your device must have gyroscopes, accelerometers, and magnetometers and a version of Android that supports these technologies. If you are not sure, you can try one of the free sensor test apps in the Google Play Market and find out.

When you press 'Start' on the main screen the app begins to prepare the device for the measurements (for 10 seconds). During this time, place the device on the subject's chest. Once the measurements begin, the 'Start' button changes to 'Busy.' The measurements take about 20 seconds. Once the measurements are done, the breathing and heartbeat rates (in bpm) are shown, as well as the amplitudes of each. Also shown are plots of the breathing movements and the average movement ('pulse') due to the heartbeat (as angle versus time in arbitrary units).

With the second method, you place your fingertip on the device's rear camera and light for 25 seconds. The app monitors the brightness changes resulting from the changes in blood flow through your fingertip.

With these two methods available in the same app, virtually any Android device can be used to measure heartbeat rate. This is also the only app that gives the user an indication of the quality of the measurements.

If you find this app useful, please consider supporting us by buying the Pro version, which uses the same measurement 'engine' as this free version. If this version works well on your device, then so will the Pro version. The Pro version adds 'settings' and 'history' menu opitons. The settings screen gives you the options to save heartbeat and breathing rates to a file, 'speak' the results of the measurements, turn the 'ping' sound off or leave it on, and increase the number of 'rounds' of measurement (additional rounds do not require the prepare step). The history screen lists the values of the previous measurements since the history was last cleared. Also, the Pro version does not have ads.

New features

Version 2.5: app now only uses portrait mode, as rotation of the screen sometimes caused problems. Also, the app can now be installed to an external SD card.
Version 2.6: fixed some UI issues with larger devices. Fixed some problems with access to camera on some devices. Now ask user on first use of the device has a rear camera.
Version 2.7: minor performance improvements.
Version 2.8: fixed a bug that caused app to hang on the review request page.
Version 3.0: Fixed menu on newer devices.

App Permissions

Allows applications to open network sockets.
Allows applications to access information about networks.
Allows an application to write to external storage.
Allows read only access to phone state, including the phone number of the device, current cellular network information, the status of any ongoing calls, and a list of any PhoneAccounts registered on the device.
Allows applications to access information about Wi-Fi networks.
Required to be able to access the camera device.
Allows an application to record audio.
Allows an application to read or write the secure system settings.
Allows applications to connect to paired bluetooth devices.
Allows applications to discover and pair bluetooth devices.
Allows using PowerManager WakeLocks to keep processor from sleeping or screen from dimming.
Allows an application to read from external storage.