Biorhythm-Shareware:

WINdows-Biorhythm-Programmes

Adrian Fourie wrote a program called StarLove: It matches two people's birthcharts as well as their progressed charts for compatibility.

Mac-OS

Dashboard Utility (OS-X):

Biorhythms-Freeware-Programme

Biorhythm-Programme «Bio (2.3g/e)» for

Print your Biorhythms and those of your friend in nice colours.

Bio-2.3g/e calculates and prints your and your partners biorhythms. A partner-analysis shows, how harmonious your rhythms are. Languages: English, German, French and Italian.
Download Biorhythm-Shareware-Programme Bio-2.3-g/e for  Mac-OS-9 click here! (download)