This little C# program can download data form the BH3 in CSV format. It is compatible with Mono, so it should run everywhere. It just excepcts unix-style devices to do serial communication with. It was never tested on Windows.
It is based on the example code of the BioHarness Bluetooth Developer Kit but all the Windows-specific and Mono-incompatible parts where removed.
It's easiest to use Xamarin Studio to build this solution.
You may have to change the device name. The BH3 usually appears as something
like /dev/tty.usbmodemfa131 if connected via USB and /dev/tty.BHBHT007929-iSerialPort1 via Bluetooth.
You can specify the device location as the last argument on the commandline or change the strings in the source.
Downloading CSV files via Bluetooth is not possible, but listing the sessions is.
Deleting sessions and doing fancy things is not possible (yet).
$ mono BH3_Tools.exe list
Welcome to the BioHarness 3 Log Downloader
Checking Serial Device /dev/tty.usbmodemfa131
Available Sessions:
Session 0
===========================
= When: 3/14/2014 8:28:29 AM
= Dur.: 10h 17m
= Size: 37041kb
===========================
Session 1
===========================
= When: 3/16/2014 5:30:07 PM
= Dur.: 0h 37m
= Size: 2243kb
===========================
$ mono BH3_Tools.exe download 1
Welcome to the BioHarness 3 Log Downloader
Checking Serial Device /dev/tty.usbmodemfa131
Downloading Session 1
Session 1
===========================
= When: 3/16/2014 5:30:07 PM
= Dur.: 0h 37m
= Size: 2243kb
===========================
Transmitting data...
Received 2296832 bytes.
Saving files in /Users/tobi/BH3_Tools/
Done.