Originally written for the Nokia 9210 Communicator in early 2002 and thus probably the oldest biorhythm app for smartphones, Biorhythms Pro has been ported to Harmattan.
As the name suggests, the program is a mobile personal biorhythm calculator, providing features missing from other applications of this type currently available for the Nokia N9. It allows storing two persons' data (birth dates and names) and switching between them with one tap. It provides biorhythm interpretation (textual explanation of what the current state means) and scrollable graph to quickly and easily change the date for the biorhythm reading (it can also be selected manually using a date selector, which is easier for distant dates than scrolling the graph). It also warns about critical days.
Its main screen is divided into three parts: buttons to select person, detailed biorhythm levels for the selected day (with some additional information like the number of completed cycles, day of current cycle, whether the biorhythm is currently rising or falling, etc.) and a scrollable graph.
Interpretation of the current biorhythm reading is available via the "Interpret" button. The program also contains a help page informing how to use the application, and a history and explanation of the biorhythm theory.