GetBiorhythms Calculator Portable Free. Itis a rather simple application that allows you to keep track of your daily biorhythm. With the help of this application, you can find out what are the most likely best and worst days. The information is created by using your birthday. Since it is a portable application, you will not have to undergo any installation process prior to using it. You can use it when you require and then remove it. It will not leave any trace behind in the Windows Registry once it has been deleted.